Chapter 9 - Imposed Group Structures

THIS CHAPTER WILL DISCUSS: 
1. Networks that are imposed on groups regarding who can communicate with whom. 
2. How these imposed networks affect group process and output. 
3. The media forms that group members can use to communicate with one another. 
4. How these communication media affect group process and output. 
5. The effect that computer conferencing has on group process and output. 

INTRODUCTION

Structural Perspective
We have discussed aspects of the structural perspective in earlier chapters, and we return to that perspective now. This time, however, we approach it from a different angle. 
Earlier we discussed the issues of conflict, power, and conformity/deviance in relation to this perspective. In those cases, what we examined came out of the usual structuralist view of norms and roles, which is that, as group members continue to interact over time, various norms and roles emerge. Norms and roles, then, are the structures that form within groups. 
Many groups, however, cannot let their roles and norms emerge naturally from interaction. Instead, they find themselves working under imposed structures. This happens frequently when people form groups within organizations. Outside forces, such as the head of a company, control how the people must interact in the group. Structures are often imposed on organizational groups in this way. 
We can organize these imposed structures into two overall types: the structure that restricts who can communicate with whom in a group, and the structure that restricts how group members can communicate with one another. An example of the first type is a company group in which the members must communicate with one another through one manager. They cannot give information directly to one another. An example of the second type is a group in which members cannot meet face-to-face but must make their decisions via telephone or written messages. 
In effect, someone can impose a structure on a group by controlling the way members communicate. Communication is the key and both reflects and determines structure. Organizational groups are an example. Companies often impose lines of authority and methods of message exchange on their workers. A structural theorist would say that an organizational hierarchy, or chain of command, is a structure of imposed roles and norms. This structure, in turn, helps to determine the authority and influence patterns among the members of the organization. 
Hence, structural theorists are able to use their viewpoint to examine imposed structures. They see norms and roles within the imposed interaction. Further, researchers treat both types of imposed structures as input variables. By doing so, they are able to examine the effect of the structures on group process and output variables. The findings help them determine which structures best meet different organizational needs. 
Three Areas of Research
In the following sections we will explore the research that scientists have done on imposed structures. First, we will examine research on structures that restrict who can communicate with whom in a group. Scientists have come to call these structures "communication networks." Second, we shall discuss studies that have looked at structures that control how group members can communicate with one another. These studies compare communication that takes place face-to-face with communication that utilizes various media, including telephone, teletype, and closed-circuit television. Third, and last, we will describe how the use of computer conferencing also acts as an imposed group structure. 

IMPOSED COMMUNICATION NETWORKS
Early Work
Ideas about imposed communication networks combine theoretical and practical concerns because people in organizations frequently work with them. These concerns have led to a rather large body of literature on the effect of imposed networks. Scientists have been interested in how such structures affect group process and output. A great deal of research was done, in particular, in the 1950s and early 1960s. 
Problems plagued this early research. Because few strong theoretical positions emerged from it, by the mid-1960s theorists had lost interest in pursuing experiments about imposed networks. Hence, the research about imposed networks dates from the 1950s and early 1960s. Despite their weaknesses, these early efforts did produce some interesting and useful findings. A study of these efforts provides a great deal of information about how one can approach a topic, such as imposed networks, and create appropriate experiments. In this way we help fulfill one goal of this book, that of helping the reader to understand how a scientist works. 

Possible Networks for Groups 
We will begin by describing possible networks for five-person groups. In Figure 9.1, we show five possible structures. Each number represents a group member. The lines represent possible channels for message exchange. In each case, these channels allow two-way communication. The members who are linked by lines can send messages directly to each other. Other group members are indirectly linked. They can send messages only with the aid of intermediaries. Either directly or indirectly, all members can communicate with one another. 
FIGURE 9.1 
When evaluating these diagrams, we need to consider four important indices. They relate to the imposed group network under study and are a way that scientists can measure interaction and quantify a group's network of communication. 
Distance 
The first index is distance, which is the number of links between any two members. The shortest distance is one. For example, the member at the center of the wheel configuration needs only one link to reach an outside member. The members communicate directly through one line of message exchange. The longest distance for any five-member group network is four, which occurs when members are in a chain structure. Four is the number of links that each member at the end of the line must use to get a message to the other end member. 
Summed distance 
The second index is summed distance, the number representing the group members on the diagrams. Remember that "distance" is the number of links a member must use to communicate with other members. To compute the summed distance, we add the distances it takes for one member to reach each other member in the group. This is not a group total. It refers only to each individual member. For example, the summed distance for the central member of the wheel is four. It only takes four links for that member to communicate with all other people in the group. The summed distance for each of the other four members of the wheel configuration is different, however. An outside member would have to use seven communication events to communicate with all other group members. The figure "7" applies because only one link is needed to talk to the central member, but two links are needed for each of the other three. Thus, the wheel diagram shows a "4" for the central member and a "7" for each of the other members. The summed distance is important because the structure of a group is based only on this criterion. The way in which we draw each group is arbitrary. The diagrams may look like a "wheel" or a "circle" here, but the actual group configurations might be very different. For example, if 

it would still be a "Y" group. The reason is that each configuration still has members with the right summed distance for the "Y" group. 
Another example is the wheel group. The previous diagram makes the wheel look like a centralized structure that differs from the "corporate ladder," or hierarchy, approach. However, looking at the standard hierarchy we can see that they both have one member with a summed distance of"4" and four members with "7." The wheel and the hierarchy are the same structure. 

Position centrality 
The third index is position centrality, which rates how central or peripheral a group member's position is. It is based on a comparison of summed distances of group members. In a wheel group, for example, one member has a lower summed distance, "4," than the other members, who have "7" each. The member with the lower summed distance is central. This person is in the middle of message flow. The others are peripheral. They are on the outside of the flow. Another way to think of it is that a group has "levels" of centrality. The chain example has three levels of centrality. Such a group has summed distances of "6," "7," and "10." The lowest number, "6," is the most central. The "Y" group has four levels of centrality. In the case of the circle and the comcon, all members have the same summed distance. In these groups, position centrality is equal. 
We can compare groups according to whether members' position centrality varies. In centralized groups, such as the wheel, "Y," and chain, some members are more central than others. 
In diffused groups, members' centrality does not vary. Groups such as the circle and the comcon fit this model. No one member is more central than another. The communication links are diffused evenly. We can make additional variations regarding how central or diffused a group is, such as degrees of centrality. This idea applies to the concept of network centrality. 

Network centrality 
The fourth index is network centrality. Scientists have proposed mathematic methods for determining this index. We will develop an intuitively simple way to create this index. We add all the members' position centrality scores, which equal their summed distance numbers. We now have a number that represents the total amount of "distance" involved if each member were to send a message to each other member; in other words, the number of messages the whole group would have to use for all the members to communicate once. In Figure 9.1, this number is next to the name of the structure. For example, the wheel has a total of "32." 
In diffused groups, each member's "contribution" to this total is equal. For a five-person group, this contribution is 20 percent. For example, in a circle configuration each member has a summed distance of "6" out of a total of "30." "Six" is 20 percent of "30." 
By contrast, members of centralized groups need fewer links to send messages to each other member. They have a lower summed distance than others. These members, therefore, contribute a lower percentage to the total of the summed distances. By observation, we would say that the wheel is the most centralized structure. Our index of network centrality verifies this. We can see that the wheel has only two levels of centrality. One member contributes only 12 1/2 percent to the total of possible communication links. The four peripheral members contribute almost 22 percent each. The person with the smallest percentage of contribution is the most central member. In a hierarchy, we would probably label this person the most powerful. He or she needs to expend the least amount of energy and time to communicate with all other group members. 
The "Y" structure has four levels of centrality; the chain has three levels. By "level" we mean the numbers indicating each member's summed distance. The amount of levels of centrality do not indicate how central a group is, however. For example, between the "Y" and the chain, the chain is more centralized. The "Y" configuration has a central member that contributes a little less than 14 percent of the group's total. Its next most central member contributes 16 2/3 percent. The chain, in contrast, has a central member who contributes 15 percent and is flanked by two people who each constitute 17 1/2 percent. This means that the chain has three members who have low percentages in comparison with the others; the "Y" has only two such clearly central members. We should remember that these percentages all apply to five-member groups only and would change for groups of other sizes. 

Further considerations 
We have two more considerations before we examine the research regarding imposed networks. 
First, the five configurations we described in Figure 8.1 are not the only ones possible. One can join the two peripheral members of a "Y," thus making a "kite" network. Or, we could join some of the members of the circle and form a network that is intermediate between the circle and the comcon. It is also possible to restrict some or all of the circle or comcon channels so that they are one-way only. This idea works only with the circle and the comcon, however. The other configurations could not restrict channels because then members could not send messages to all other members. 
Second, we have not considered group size. The larger the group, the more networks are possible. In a three-person group, only two networks are possible if we don't use one-way channels. For three people, the "Y" disappears, the chain and wheel are identical, and the circle and comcon are also the same. 
The diagrams and considerations that we have explained so far may appear abstract; however, they have concrete implications. Scientists use the ideas about distance and other aspects of the structures as bases for their research into group functioning. Research suggests that differences in position centrality lead to differences in process and output variables. Similarly, among entire groups, network centrality also affects group process and output. 
In the following section we will discuss research and the experimental findings concerning imposed group networks. We will begin with a description of how the experiments were performed. 
Research
Methodology 
Theoretical work by Bavelas (1950) suggested the potential value of research on imposed group networks. Shortly thereafter, scientists devised a method for controlling the message linkages among group members. In this way, research on imposed networks could begin. 
Consider a five-person group. In an experiment, each member is seated at one of five adjacent cubicles. Walls with slots separate the cubicles; written messages can be sent through the slots. An experimenter can impose any of the possible group networks on the group's message exchange by varying which slots are open and which are closed. Keeping all the slots open, for example, produces a comcon network. If the researcher allows message exchange between only adjacent members, a circle network results. Some studies have used messengers or intercoms between group members in different rooms rather than slots between cubicles. Any of these experimental situations creates an environment in which groups work under the constraints of various structures. In this way, theorists can compare the effects of different structures. 
Early studies on imposed networks employed a problem-solving task requiring input from all group members. The experimenter gave each member of a five-person group a card. On the card were five of the following six symbols: 

The symbols were combined on the cards so that each member's card had a different pattern. One symbol, however, appeared on all five cards. The goal of the task was to discover which single symbol the cards all shared. It became known as the "common symbol" task. Once the symbol was discovered, a further goal was to inform each group member of the correct answer. 
The research design placed each group member in a cubicle with a box that had six switches. Each switch corresponded to a symbol. A group member that either discovered the common symbol or was informed what it was could flip the switch corresponding to that symbol. The experimenter sat nearby in a booth that had a bank of lights connected to the group members' switches. When the group member flipped a switch, a light showed the researcher which symbol the member had chosen. This setup allowed the members to quickly reveal when they had finished their work. The group completed the task when each member had switched on a light. The researcher could thus note both the speed and the accuracy of the group's performance. 

Experimental Results 
Leavitt's (1951) experiment was the best known among these early experiments. Five-person circles, wheels, "Y" groups, and chains performed 15 trials of the common symbol task. 

Network centrality 
The effect of network centrality on the groups was fairly consistent. It affected speed, accuracy, and group process. In general, the more centralized the group, the better it performed. The wheel, the most centralized configuration, was slightly faster than the "Y" groups. The wheel averaged 32.0 seconds and the Y group averaged 35.4 seconds. The circle, at 50.4 seconds, and the chain, at 53.2 seconds, were far slower. 
Group process followed a similar pattern. Wheel group members sent the fewest messages, with the "Y" and the chain coming next, and circle groups sending the most messages. The wheel and the "Y" networks also made fewer errors than the circle and the chain. 

Position centrality 
Position centrality also led to consistent findings among the groups. The more centralized the group, the more often and the more unanimously the members judged that the group had a leader. In the chain, the most centralized member received the majority of leadership "votes." The two adjacent members, who are more central than peripheral, also obtained votes. With the "Y" configuration the two most central members split the votes. The choice of the central member of the wheel was almost unanimous. Also, the most central members sent the most messages. 

Maintenance output 
The different group networks also affected maintenance output during the experiments. Overall, members of centralized groups were more satisfied with their groups' performances than were members of less centralized configurations. Peripheral group members of centralized networks, however, were not so satisfied with their personal jobs in the group. This situation might mirror, for example, the situation of an army private, Paula. She is satisfied with the way the army is winning a war but not so pleased with the job that she has to do to help the army complete its task. 
Diffused group members had a relatively high personal satisfaction level even though diffused group members were not as satisfied with their group's performance as centralized network members were. For example, Paula may not be satisfied with the efficiency of a circle of her friends when they get together and plan a party, but she is happy with the equal part she plays in the planning process. 
Of all the groups, however, central members of centralized networks liked their jobs the most. For example, the general in Paula's army is probably happier on the job than the soldiers. In the experiments, however, a centralized group's overall satisfaction was lowered because peripheral members expressed a strong dislike for their jobs. Their unhappiness offset the central member's satisfaction. The differences in job satisfaction between central and peripheral members increased as time went on during the game trials. For example, the general in a centralized army would become happier over time, and the privates would grow less content. Also, differences in the levels of satisfaction increased as a group became more centralized. This might happen if a group went from a chain, through a "Y," to a wheel. 

Explanation of results 
We can account for the consistencies in these experimental findings by considering two principles we have already discussed: (1) the demands of the task and (2) the opportunity for group members to communicate. These two principles are interrelated. For example, an easy task may not require as much communication as a more difficult task. Both principles affect group process and output variables, such as performance and level of satisfaction. As we discuss the experiments and that behavior patterns are consistent with what an experimenter might expect, we will keep in mind both these principles. 

Task demands 
The "common symbol" problem is an accuracy task. As discussed in Chapter 2, this means that the group's task performance is based on the performance of its most competent member. In other words, when one person solves the problem, the whole group is successful. Now, the task itself is simple. Anyone with sufficient information about the symbols on all the cards can perform it. It is not a problem that would involve analyzing complex data or making a difficult judgment. Thus, the most competent member is simply the member who can most easily accumulate the information about all the cards. 
In a centralized group network this competent person is the most central member. He or she can best learn which symbol is on everyone's card. Even a diffused group can work efficiently on this task if it chooses to exchange messages via a centralized organization. Comcons can easily act as wheels, and circles can easily act as chains, if group members ignore some of their message exchange channels. This choice is not natural, however, and it seldom occurs spontaneously. Therefore, truly centralized groups are more likely to organize themselves in the manner most efficient for solving the problem of finding the common symbol on the cards. 

Communication "organization" 
Leavitt's observations on how his groups exchanged messages support this last claim. He examined how organized his groups could become through their communication. By "organized" we mean that they began to send messages in a consistent pattern from trial to trial. The centralized wheel groups generally became organized by the fourth of 15 trials. They also generally adopted the efficient method of sending information to the central member. This member found the common symbol and informed the other group members. 
The "Y" group members also generally organized themselves efficiently, although it took a little longer for them. Chain group members usually, but not always, became organized. Their organization often placed major responsibility on one of the members adjacent to the central member. This pattern is sufficient but not optimal for task performance. It may be at least partly responsible for the chains' relatively poorer results. 
Leavitt did not find any consistent organization to develop in circle groups, the least centralized configuration. Later researchers decided that such diffused groups did have something of an organization. They saw a pattern naturally developing, and called it "each-to-all." In this "organization" each member sent information to all others. Such a pattern is definitely not efficient for solving the common symbol problem. 

Organization and efficiency 
Let us study the issue of efficiency more closely. A well-organized wheel, with five members, requires eight messages to complete its task. Each peripheral member will send one message to the central member and the central person will send four messages back to the peripheral members. For example, after getting their cards, the four members in cubicles encircling the central member will write notes telling which symbols they have and put the notes through the connecting slots. This makes four communication "moves." The central member then looks at the cards finds the common symbol, and quickly tells each other member the answer, in turn, through the slots. These four additional notes total eight messages. 
Centrally organized "Y" groups and chains also require eight messages; however, the need for using intermediaries for messages slows the groups slightly. Comcons that are organized in "each-to-all" patterns require each member to receive information from each other member. The members then must make individual decisions on the common symbol. This requires 4 messages from each member, or 20 messages in all. Such organization leads to slower work than centralized configurations. The opportunity for error is also greater. 
We can use these considerations to examine group process and task output. As we have noted, some tasks, such as the common symbol problem, are best performed by a centralized group pattern. Wheel, chain, and "Y" groups have an imposed network that predisposes them to adopt centralized patterns of message exchange. These groups will become centralized more often and more easily than groups that do not have such an imposed structure. They will then perform tasks such as finding the common symbol more quickly and accurately than diffused groups. 
In addition, an organization that emphasizes its central member will need to send fewer messages to complete the task than, for example, a group using an "each-to-all" pattern. The central member will send the greatest proportion of messages. He or she is also the sole problem-solver, and other members will judge such a central person to be the leader. In the "Y" group and chain configurations, one or more central member may share in or perhaps take over the problem-solving responsibility. In that case, the other central members will also receive some recognition for leadership. 
As we can see, the demands of the task bear directly on which group organizations function best. 

Maintenance output and task 
We need to consider the impact of the task on organization again as we examine Leavitt's results for maintenance output. 
In a centralized organization, the peripheral members have little opportunity to exchange messages in comparison to the central members. They also have fewer opportunities than members in an "each-to-all" group. With the "common symbol" task, however, centralized groups are more successful than others. As we would expect, peripheral members in a centralized configuration are more satisfied with their group's performance than less centralized groups because the latter do not perform as well. Also as we would expect, peripheral members in a centralized organization are dissatisfied with their own role in the group. They have little opportunity to communicate and are not directly involved in solving the problem. They are the "soldiers" in an army hierarchy. 
In contrast, central members of centralized configurations and all members of diffused groups are more personally satisfied. We would expect this because these members have a greater opportunity to communicate. Central members, however, were even more satisfied than diffused group participants, in part because of their greater personal responsibility for the group's performance. In addition, central people may be more content because their group has a greater overall performance. 

Organization and group performance 
The manner in which a group organizes itself appears crucial in determining the group's performance. Several implications follow. 
First, the communication "organization" of groups improves as the group members become more experienced at problem solving. For a problem such as the "common symbol" task, groups develop over time so that they need to exchange fewer messages. Thus, they can solve the problem faster. They also become more satisfied with the group as the group does its job well. Further, there is evidence that performance differences among imposed networks disappears a large number of trials. Burgess (1969) asked four-member wheels and circles to perform the "common-symbol" task for 10 hours. At the beginning, circle groups were slowest, as in the Leavitt study. However, as time passed, circle groups improved their performance more quickly than wheel groups. By the tenth hour, the groups had solved the problem more than 500 times, and there was no difference in speed between circles and wheels. This finding suggests that any group can adopt a successful organization for its task. All the group needs is experience. 
Second, some evidence indicates that groups can plan an efficient structure for themselves. Researchers have shown that message exchange may be more efficient if a group is given an opportunity to plan an organizational pattern before performing its task. Such planning results in a relatively faster performance by groups with diffused networks. 
Third, groups try to maintain their imposed networks if those structures are effective. If a group has developed an efficient organization under the constraints of one imposed network, the group will maintain that organization as much as it can under a different imposed network. For example, an efficient centralized group can maintain its organization if a comcon setup is imposed. Such a group will actually tend to keep its original organization. In contrast, the change from a comcon group to a centralized configuration may require some adaptation. Further, the maintenance effects of this last change are predictable. Central members have job satisfaction that rises, but at the expense of members who are suddenly peripheral. 

Additional Research 
We have been examining experiments using the "common symbol" problem. Other tasks place different demands on a group. 
As we have discussed, task demands determine optimal communication "organization." Organization, in turn, affects all phases of group functioning, such as the level of satisfaction and performance. Consequently, tasks other than the "common symbol" may entail different organizational patterns and results for group functioning. For example, structures that were efficient for the "common symbol" problem may not be efficient for other tasks. 
Shaw (1954) performed a study in which four-person groups solved simple arithmetic problems. As did Leavitt, he imposed different structures on the groups. An example of the type of mathematic problem that he used is: 

How many trucks are needed to move a company's office equipment if it owns 
(a) 12 desks, (b) 48 chairs, (c) 12 typewriters, and (d) 15 filing cabinets and if 
one truck can carry either (w) 12 typewriters, (x) 3 desks, (y) 5 filing cabinets,  or (z) 24 chairs? 

Shaw gave each group member a general description of the problem; however, the participant received only two pieces of the information necessary to solve the problem. For example, the group member would see one item out of "a" to "d" and one item out of "w" to "z." Further, the two pieces of information that each participant received were never about the same items of office equipment. Thus, if someone was told how many desks the company owned, he or she would never be told how many desks a truck could move. The latter piece of information would go to another member of the group. 
The results of Shaw's research were generally the reverse of the Leavitt study. The circle was fastest and best at correcting errors. Group members in this network saw themselves as the most cooperative and the best performers. They also enjoyed the task the most. In contrast, the wheel ranked last in all these variables. 
To account for the differences between his groups and Leavitt's, Shaw emphasized the different tasks. The demands of Shaw's arithmetic question were different from those in Leavitt's "common symbol" problem. 
As we have shown, Leavitt's groups attempted to solve a problem requiring only that the members collate information. For reasons we have discussed, this type of task is best performed in a centralized group. In such a group the central member can assume primary responsibility to collate the necessary information efficiently. 
In contrast, Shaw's groups performed a task with two requirements. Group members not only had to collate information but also needed to perform arithmetic operations once they had the information at hand. Shaw reasoned that this experimental task placed too much responsibility on the central member of a centralized group to handle the problem efficiently. Instead, group members can most efficiently solve the mathematic problem by splitting it into parts with different people, or subgroups, working on each part. The work becomes, in effect, a multiple stage accuracy task. As you recall from Chapter 2, multiple stage accuracy tasks are best performed when group members divide the stages among them. Diffused structures most easily allow this division. Thus, circle group members perform this task better than wheels. In addition, circle group members enjoy themselves more because their diffused group organization allows them greater opportunity to communicate. 
Other studies have been performed in order to compare diffused and centralized structures performing "common-symbol" and arithmetic tasks. The results of this research is consistent with our conclusions. In reviewing this work, Burgess (1969) found 13 studies of "common-symbol" tasks. Centralized networks were faster in seven of these, diffused networks were faster in three, and there were no differences among networks in the other three. Burgess also found ten studies of arithmetic problems. In this case, diffused networks were quicker in six, and centralized networks quicker in only one, with no differences in the other three. 
There are other types of accuracy tasks that diffused groups perform well. For example, Davis and Hornseth (1967) had individuals and five-person groups in wheel, circle, and comcon networks work on "eureka" problems that required creativity and insight. In this study, the comcon sent the most messages and was both fastest and most accurate. 
In addition, the experimenters rated the groups. They took the results of the individuals and used the Lorge/Solomon Model A (see Chapter 2) to estimate, without losses from faulty process, the performance of the five-person groups. None of the groups reached this estimate, but this usually occurs in disjunctive tasks. The comcon groups, however, came closest to matching the estimates. The comcon appears flexible enough to allow the group's most competent member to take responsibility for solving the problem. The problem-solving member will then successfully influence the rest of the group more often than not. Centralized networks, on the other hand, lack this flexibility. In those groups, central members tend to become most influential, regardless of whether they are the most competent at the task. 
These two studies examined tasks that needed to create or manipulate information. We can conclude that when a group is faced with such a task, in any fashion, the diffused structure leads to better results than the centralized structure. Diffused networks produce better task and maintenance group output in such cases. Centralized networks, such as the wheel, appear to be of value only when their function is to relay information quickly and efficiently. We can see networks such as the wheel at work in the strict hierarchies officially imposed in the military, for example. Based on the research above, we can infer that the military's structure would lead the army to be better at transmitting data, for example, than it would be at inventing a new tool. The army eventually could do both tasks, but research suggests that it would take the army longer to invent a tool, and perhaps with less satisfactory results, than a more diffused network, such as a circle of inventors. 
As always, however, we must be careful not to overgeneralize. For example, conflict might make a diffused network less effective. Comcons have a large amount of message exchange, which increases the risk of conflict. In contrast, centralized networks impose restraints that lower the odds that conflict will occur. If a group wants to avoid conflict, a more open communication network may be too risky. The benefits from the restraint of a centralized structure may outweigh the advantages of a diffused network. (Recall the advantage of using intermediaries in conflict negotiations. Intermediaries are analogous to central members of a centralized group.) 
In another example, a group of people who have never met may be too uncomfortable to participate freely in the give-and-take of a diffused organization. If the atmosphere is tense, the group will have trouble accomplishing its task. To solve the problem, group members could work through an intermediary, or central member, who could make the group members feel more comfortable. 

General Conclusion 
The main conclusion of these studies is that the group's goal is very important. The choice concerning whether to restrict the structure of who-can-speak-to-whom depends on the group's goal. 
As we have seen, studies have examined the effects of restrictions on who-can-speak-to-whom in groups. We call such restrictions "imposed networks." We can find examples of imposed networks throughout society, ranging from an official company brainstorming circle that encourages all members to speak, to a military hierarchy that places power in the hands of a few. Various networks affect group process and output in different ways; however, the results always depend on the group's task. For example, if a task mainly involves relaying information, the centralized group is effective. Group members in such groups are satisfied with their group's performance and complete the task well. By contrast, a task that involves creative problem solving acts differently on a group. A diffused group network generally leads to the best results with this kind of task. 

MEDIATED GROUP DISCUSSION
Now we shall examine group discussions that members conduct through various forms of communication media. During the 1970s, researchers performed many studies that compared this kind of discussion with face-to-face group discussion. 

Types of Channels
We can classify these forms of media according to the communication channels they include. The channels are visual and audio. In other words, these media differ in terms of whether they let people see or hear one another. The four forms of mediated group communication are: 

1. Audio and visual channels. This form combines the two channels. It includes discussions in which group members who are in different rooms can both see and hear one another. Members usually use close-circuit television to conduct this form of discussion. 

2. Visual channel. In this case, group members are in different rooms that are separated by glass partitions. Members can see but not hear one another. They can use only written communication--handwritten, typed, or teletyped messages. Researchers have even used arcane "remote handwriting" systems in which a person writes with a pen in one room while a mechanical pen duplicates their hand movements in another room. 

3. Audio channel. Here, group members in different rooms cannot see one another. However, they can speak with one another through telephone or microphone and speaker systems. 

4. Neither channel. In this case, group members are in different rooms and can neither see nor hear one another. To communicate, they can send written, typed, or teletyped messages. 

"Social Presence" Theory of Short et al.
According to Short, Williams, and Christie (1976), each form of media should affect group process and output differently, because the fewer channels of communication available, the less information people can transmit. Let us examine their argument. To do so, we must first distinguish between verbal and nonverbal behavior. Verbal behavior consists of words and sentences. Nonverbal behavior consists of body movements, body positions, and facial expressions. Nonverbal behavior also includes what are called "paralinguistic cues," vocal characteristics that accompany speaking, such as the rate and pitch of speech. 
People give meanings to nonverbal behavior. When they look at nonverbal behaviors, they use what they see to form judgments about how people relate to one another. Researchers have done many studies to try to discover how people interpret nonverbal interaction. The studies have investigated the sorts of judgments people make when they see different amounts and types of nonverbal behaviors. 
Mehrabian (1973) reviewed these studies. Mehrabian concluded that scientists can classify nonverbal behaviors according to three dimensions: immediacy, relaxation, and responsiveness. Each dimension corresponds to a type of judgment. These judgments concern how people relate to one another and are based on the nonverbal behaviors that people display. Different behaviors help people judge different aspects of a relationship. In essence, a researcher can look at a nonverbal behavior and ask, "What type of judgment would people make about this relationship based on what they have just seen?" For Mehrabian, the answer would come from one of his three dimensions. 
The first dimension consists of behaviors that signal "immediacy," or liking. How much do people enjoy being together? This type of judgment concerns the degree to which people like each other as they interact. Many nonverbal behaviors indicate immediacy. They include variations of the following: touching, interpersonal distance, eye gaze, facial expressions (such as smiling and frowning), head movements (such as nodding), forward lean, and body orientation toward one's interpersonal partner. 
Mehrabian's second dimension includes actions that signal "relaxation." These behaviors reveal the relative power that interacting people have. In Chapter 5 we discussed the kinds of behaviors that show the levels of power that exist between communicators. Of these, Mehrabian particularly stressed arm and leg positions and sideways lean. 
The third dimension involves actions that show a person's "responsiveness," or attention, to others in an interaction situation. Such actions signal how much attention a person is paying to his or her interacting. Nonverbal behaviors that indicate responsiveness include paralinguistic cues such as a person's speech rate and the amount of variation in speech volume and pitch. 
Thus, we use nonverbal behaviors as clues. They help us judge how much people like one another, how much power they have relative to one another, and what attentiveness level they have as they talk. 

Effects of Media on Nonverbal Interaction 
All of this changes, however, when people conduct their discussions through media rather than face-to-face. When people don't talk face-to-face, nonverbal behaviors cannot play the interactive functions we delineated above. 
For instance, if people use a medium that does not include an audio channel, they cannot hear the paralinguistic cues that help them judge attentiveness. Similarly, when the medium does not include a visual channel, people lose all the body movement and position cues that help them judge levels of liking and power among people. Even closed-circuit television may remove the most important indicators of power if the picture includes only people's faces and upper bodies, rather than their entire bodies. 

"Social Presence" 
Short, Williams, and Christie (1976) examined what happens when group members communicate through restricted channels rather than face-to-face. They concluded that, overall, such restrictions lower "social presence" in groups. "Social presence" is the feeling among group members that they are communicating with people instead of with impersonal objects and that these people have unique personalities and real emotions. When social presence is high, each group member has a feeling of "joint involvement" with the other members. This feeling is absent if social presence is low. 

Effect on group maintenance 
When social presence is low in a group, the group fails to become cohesive and does not develop a stable structure of roles for its members. The group thus finds it difficult to perform maintenance functions. 
Different media restrict communication in different ways. The more severe the restrictions, the lower social presence becomes. "Informationally poor" media, including written messages, restrict communication rather severely. These media will lower social presence and threaten group maintenance. "Informationally rich" media, including closed-circuit television, on the other hand, place relatively few restrictions on communication. These media heighten social presence and preserve group maintenance. 
If we were to call face-to-face interaction a "medium," it would be the most informationally rich of all. It best helps groups maintain themselves. We do not, however, label face-to-face interaction as a medium. Hence, when we say "mediated discussion," we mean that group members are not meeting face-to-face. 

Effect on group task 
One may think that the absence of visual and audio channels would have little effect on how well groups perform their tasks. After all, groups use verbal communication to do their tasks. Even the most severe restrictions, which deny members the use of audio and visual channels, should not impede them. As long as members can send written or typed messages, they can successfully perform tasks. We saw proof of this in our discussion of imposed communication networks. Group members who had to work under severe restrictions solved common-symbol, arithmetic, and eureka problems. 
Perhaps we should not, however, be quick to assume that groups can perform tasks even with severe restrictions on communication. As we have seen, Short et al. hypothesized that media that restrict communication lower social presence in groups. This, in turn, lowers the cohesiveness level and creates group maintenance problems. In Chapter 8 we discussed Bales's hypothesis of the "equilibrium problem." He felt groups had to balance their maintenance and task needs to be successful. If Bales was right, groups that have maintenance problems will eventually have task problems. Therefore, groups may harm their ability to do their tasks well if they use communication media for their discussions. 
Let us keep in mind the arguments behind social presence theory as we go on to look at research into how media affect groups. 

Research into the Effects of Media on Task Performance
Is it true that restrictive media can harm task performance? Scientists have performed many studies to try to learn more about this issue. Research findings showed that the answer depends on the type of task. 

Tasks with Objectively Correct Answers 
Some group tasks require an objectively correct answer. Researchers can judge the accuracy of the outcome. Studies have examined these kinds of tasks to see how they respond to communication restrictions. For example, Chapanis, Ochsman, Parrish, and Weeks (1972) formed two-person groups and controlled the communication channels--face-to-face, audio only, teletype, or written notes. The groups had two tasks: (1) to find the office of a physician closest to a certain home address and (2) to assemble a trash can carrier. Thus, both tasks had objectively correct answers that the researchers could measure. 
The study found that participants who could only write or type messages to each other took longer to perform the tasks than the participants who could speak with each other. Most people take five to ten times longer to type or write a message than to say it. This time difference, however, did not affect the quality of the answers. In the end, the media by which groups could communicate did not affect how well they succeeded at their tasks. Other similar studies have found the same results. When tasks require objectively correct answers, the medium a group uses has no effect on the correctness of its answers. Groups can succeed at these tasks even under heavy communication restrictions. 
Tasks Without Objectively Correct Answers 
What about other types of tasks? Conflict and negotiation tasks, for instance, have no objectively correct answers. Studies of these kinds of tasks lead to different conclusions about the effects of communication media. 
Wichman (1970) conducted one of these studies in which participants played 78 trials of a Prisoner's Dilemma Game. The communication channels they could use were (1) neither audio nor visual, (2) audio only, (3) visual only, or (4) both audio and visual. Wichman measured how often participants cooperated with one another in each condition. The percentage of trials in which cooperation occurred in each of the four conditions is shown in Table 9.1. 

Table 9.1		Visual		
		Yes	No	
Audio	Yes	87%	72%	
	No	48%	41%	
As you can see, cooperation was much higher when participants could hear one another than when they could not. In contrast, cooperation was only slightly higher when participants could see one another than when they could not. Therefore, vision appeared to affect cooperation only a little bit; the effect of hearing was very strong. 
Morley and Stephenson (1969, 1970) did another study of tasks that do not have objectively correct answers. They asked two participants to role-play a session in which two sides, union and management, were negotiating about wages. Each participant took one or the other side. They negotiated either face-to-face or by telephone. The participants had information about the "facts" of the situation, which the researchers had slanted so that one or the other side had a more reasonable case. Morley and Stephenson found that the side with the better case was successful more often when the negotiation was over the telephone rather than face-to-face. Apparently, on the telephone the negotiations focused more on "facts" than on the needs of the negotiators. 

Interpretations of Study Results 
Let us review the studies that we have just discussed. One group of research involved how media affect accuracy tasks. The other examined the effects of media on conflict and negotiation tasks. Let us compare the two sets of findings, while keeping in mind social presence theory. 
The social presence theorist would say that the study results are understandable. Media affected task performance according to whether the tasks required a high level of social presence because media affect social presence. 
For instance, the studies found that media had little effect on how well groups completed tasks that have objectively correct answers. A social presence theorist would say that this is true because groups do not need a high level of social presence to do accuracy tasks well. When a group works on such tasks, it does not need to perform the sorts of maintenance interactions that communication media can affect. Therefore, mediated discussion does not affect the accuracy of groups. 
In contrast, research found that media did affect tasks that do not have objectively correct answers. The social presence theorist would say that this happens because the level of social presence in groups affects how they perform these tasks. The more "informationally poor" the media in use is, the more impersonally people treat one another. When they behave impersonally, they are less cooperative in Prisoner's Dilemma games, and they more often use the "facts" of a case to decide negotiations. 
Further, even the verbal content of negotiations seems to be more impersonal when people use informationally poor media. Stephenson, Ayling, and Rutter (1976) gathered participants who had different views on management-labor relationships. They then asked them to discuss union-management negotiation problems. The discussions lasted 15 minutes and were either face-to-face or audio only. The researchers found that audio-only discussions were more task-oriented and less maintenance-oriented than face-to-face discussions. 

Research into Other Effects of Media
Emergent Structure 
Another of Bales's beliefs was that decision-making tasks require groups to form structures of roles for their group members. How do groups form role structures? As we will discuss more fully in Chapter 11, some members will tend to dominate their group's discussion. As a consequence, they take on leadership roles. The other members will be quieter and will take on different roles. In essence, groups establish role relationships by a definite process. The process requires members to watch one another's behavior to determine the role that each person should have in the group. 
Strickland, Guild, Barefoot, and Paterson (1978) reenacted Bales's studies to see whether communication media could affect this process. In their study, four-member groups each met five times. They discussed "human relations" problems either face-to-face or over closed-circuit television. When the members met face-to-face, their individual behavior varied much more than when they met over closed-circuit television. When compared with the televised meeting, the face-to-face discussions had larger disparities among members as far as their individual amounts of communication. Disparities were also larger as far as the extent to which other members judged that the quantity and quality of their ideas was high. In other words, in the face-to-face groups differences were greater among the members' contributions to the discussion than they were in the televised sessions. The social presence theorist would claim that the closed-circuit television groups had an informationally poorer media that restricted them from forming stable role structures. 
When some members clearly talk more than others, as in the face-to-face discussions, leaders emerge more easily. This, in turn, makes it easier for the group to establish a role structure. Bales believed that such a structure helps groups make decisions. Hence, he would have predicted that the face-to-face groups in the study would have performed the task more easily than the other groups. Strickland et al., however, did not study which media made it easiest for groups to make decisions. 

Evaluations 

Communication media seem to affect the evaluations that people make about each other. Short, Williams, and Christie (1976) discussed the results of an unpublished study by LaPlante. In that study, a participant and a confederate played a 20-trial Prisoner's Dilemma game. Three times during the game the confederate sent either friendly or unfriendly messages to the participant. The confederate gave these messages through different media: face-to-face, closed-circuit television, telephone, or written. After the game, participants rated how they liked the confederate. 
Table 9.2 shows the averages of the rates of liking when the confederate sent friendly or unfriendly messages in all conditions. The positive numbers show liking, and the negative ones indicate dislike. In general, the richer the communication media, the more extreme the feelings of liking and disliking. As the media became informationally poorer, indifference of feeling was greater. In short, the participants made less extreme evaluations when they got less information. This finding supports the social presence idea that informationally poor media restrict the kinds of information that people need to judge whether they like someone. 

Table 9.2		Communication Medium		
Message Content	Face-to-Face	TV	Phone	Written	
Friendly	1.02	.80	.46	.34	
Unfriendly	-.93	-.96	-.70	-.03	
"Inherent" Qualities in Media 
One further aspect of social presence theory is that media have inherent differences that affect group process. In other words, a certain medium will, by its nature, affect group process in a certain way. 
When we look at informationally poor media, we can see some support for this idea. Clearly, the nature of these media causes them to restrict maintenance-oriented communication in groups. Further, evidence indicates that people perceive the differences between informationally rich and poor media. In essence, people may see inherent differences that affect groups. 
Research by Champness (1973) revealed this evidence. In that study, dyads made decisions about choice dilemmas by using various channels of communication: face-to-face, audio only, or closed-circuit television. At the end of the study, the dyads made judgments about the communication channels they had used. Ryan (1976) made a similar study. In it, groups made decisions about a personnel problem using the same media conditions as Champness's study. The groups also reviewed the communication channels they had used and made judgments. 
We can combine the results of both studies. Altogether, the participants judged face-to-face interaction as slightly more positive and aesthetically pleasing than closed-circuit television. With the audio-only medium, however, they were more critical on these issues. They felt that both face-to-face and closed-circuit television were far more positive and aesthetically pleasing than the audio-only medium. They judged that face-to-face interaction was no more "public" than the audio-only interaction, and they felt that both face-to-face and audio-only channels were less "public" than closed-circuit television. These findings clearly suggest that people prefer meeting face-to-face more than using media for their discussions. 
Conclusions
The conclusion of the social presence theorist, based on all we have discussed, is that informationally poor communication media do affect group process. They restrict the information that groups need to maintain themselves and, in contrast, encourage task-oriented information. In this situation, liking and power relationships are less likely to form. 
When tasks have objectively correct answers, group maintenance does not matter. Thus, communication media do not affect the accuracy of groups that do the kinds of tasks that objectively correct answers. Group maintenance does matter, however, in tasks without objectively correct answers, and communication media can affect how groups perform them. 
We will discuss these ideas again in the following section on computer conferencing. 

COMPUTER CONFERENCING
During the last decade, organizations have come to rely more and more on computers for many tasks, including conferencing. Computer conferencing is becoming more popular every year. 

Traits of Computer Conferencing
Organizations can connect computers through telephone lines, which allows computers to transmit information quickly. Through these computer connections, people separated by hundreds or even thousands of miles can form groups in order to make decisions. Further, a computer system can store a great deal of information, which users can later retrieve and read at their leisure. 
In face-to-face discussions and in mediated forms of discussion, members must take turns sending messages. Computer users, however, can type messages to each other simultaneously. The computer can store all these messages until group members are ready to read them. Earlier, we discussed how certain forms of mediated group discussion generally take longer than face-to-face discussions because people write and type much slower than they speak. Sending messages becomes much faster, however, if group members can type at the same time. In theory, a group of about seven or eight people ought to be able to make a decision as quickly when they are typing simultaneously as when they take turns speaking. 
Types of Computer Conferencing
Different types of computer conferencing can be classified according to whether or not the group discussion occurs at the same place and the same time. Let us start with the circumstance in which a small group meets in a specially-equipped "decision room." Each member of the group has a keyboard. At the front of the room is a large public screen that displays what the group is working on at any one time. Special "jointwork" word processing programs allow each member to make changes in the display. In a complex decision room, members can work on either the central public screen or individual computers at their seat. In this case, people can send public messages to everybody or they can send private notes to specific group members. Members can easily combine face-to-face discussion with computer conferencing in a decision room. 
The "decision network" type of computer conferencing links individuals and subgroups that are in different locations. One way a decision network can be used is to allow people to work together at the same time, rapidly exchanging messages via electronic mail. The members may be in the same building, in different buildings in the same complex, or many miles apart. This is called "synchronous" message exchange. A synchronous decision network is similar in many ways to circumstances that we have already described in this chapter, when people can interact by writing but cannot see one another. In this case, most nonverbal cues are missing from their interaction. Examples we have mentioned are the network study groups and some of the mediated discussion groups. 
Decision networks can also be used when people are hundreds or even thousands of miles apart. For example, a group might include members in Chicago, Tokyo, Moscow, and London. When it is the middle of the day in one of these locations, it will be the middle of the night in another. Therefore, it would be difficult for the group members to work together at the same time. In this case, they will participate in the discussion at different times. A group member will log on, read the latest messages from other members, and type in what they want the other members to read later. This is called "asynchronous" message exchange. 
There are both strengths and weaknesses to asynchronous message exchange when compared to synchronous. On the positive side, asynchronous exchange allows for people far away from one another to work together. It also provides people with the time to reflect on their decision and send thoughtful messages to one another. On the negative side, asynchronous message exchange will lead to a far slower decision process than synchronous. It may also be more difficult for members to coordinate their work when they are not exchanging messages directly. McLeod (1996) has hypothesized the types of circumstances in which each is likely to be better than the other. 
One may also ask why a group that can meet face-to-face would want to use a "decision room." There are in fact several potential advantages to having computers aid in group decision making. First, the use of "jointware" can simplify any necessary word processing. Second, using a computer easily allows for a record of the discussion to be kept. Third, people can use computers to control the actual process of group discussion. We will discuss this issue in Chapter 13, "Formal Procedures for Group Decision Making." 
Computer Conferencing and Social Presence Theory
Researchers have begun to explore how computer conferencing affects decision process and output. Scientists have done much of this research on groups in which people are interacting through a decision network. The group members are unable to see or to hear one another. 
Members are in a situation similar to the ones we discussed in the last section, in which groups used "informationally poor" media. What can we imply from this similarity? Initially we can hypothesize that this form of computer conferencing would be low in "social presence." We can follow that idea with several hypotheses based on the studies we examined in the last section. 
One hypothesis is that group discussion should be high in task-oriented content and low in maintenance-oriented content. Another is that the amount of participation should be relatively equal among members, which should lead the group to have problems forming a stable role structure. All these factors should not affect groups' performances when they work on problems that have objectively correct answers. It may, however, lead to difficulties with other types of tasks. Further, group members should be relatively less satisfied with decisions made through computer. 

Research into Computer Conferencing
Are these hypotheses correct? Does this type of computer conference so closely resemble groups that use informationally poor media? Particularly during the 1990s, a great deal of research has been performed to evaluate these and other ideas. However, the answers to some of these questions is still unknown. For example, some researchers have found accuracy and quality of decisions to be higher in face-to-face groups, others have found accuracy and quality to be higher in computerized groups, and still others have found no differences. As McLeod (1996) discussed, different researchers have been evaluating task performance using different tasks and different types of computer programs. Without more consistency across studies, it may be impossible to definitively answer this question.. 
In contrast, there are other hypotheses in which research findings are more consistent. We will describe some of them next. (See Benbaset and Lim, 1993, and McLeod, 1996, for more detailed discussions.) 
Participation 
Many studies have shown that the amount of participation in discussion tends to be more equal among members of computerized groups than among members of face-to-face groups. This finding is consistent with results for mediated discussion, as we described earlier in the chapter. However, this conclusion presumes that groups do not have preexisting social structures. New groups have yet to develop a social structure, and so participation will be fairly equal among members. "Standing" groups, with a history of working together, are likely to have already developed a "pecking order," and those members higher in status will probably participate more. Consistent with this idea, Benbaset and Lim's (1993) review of literature showed that equality of participation in computer conferences were greater for new groups than for standing groups. 
Even new groups can have unequal member participation if their members are aware of preexisting status differences among them. Weisband, Schneider, and Connolly (1995) formed groups consisting of two M.B.A. students and one undergraduate. The groups were asked to evaluate, either face-to-face or by computer, the conduct of a computer professional in an ethical dilemma. The members knew one another's status in both conditions. The results showed the M.B.A. students to communicate more than the undergraduate, whether via computer or in person. 
Influence 
If participation is more equal among members in computerized groups than in face-to-face groups, it follows that influence among members should also be more equal on computer. Smith and Easton (1996) studies ratings of influence that members of standing groups made of one another both before and after making a computerized discussion. The ratings made before the discussion were based on earlier face-to-face interaction. The researchers found that influence ratings became more equal after the computerized discussion. Although differences still existed, the members previously rated high on influence came to be rated lower, and the members previously rated low on influence came to be rated higher. 
As with participation, however, differences in influence can easily in introduced into computerized groups. In the study just described, Weisband et al. also found the M.B.A. students to be more influential than the undergraduate both face-to-face and on the computer. 
Minority influence is also affected in some interesting ways by computerization. McLeod, Baron, Marti, and Yoon (1997) reasoned that minority opinions were more likely to be expressed during anonymous computerized discussion, because members would be less concerned with the negative responses of others. However, they also hypothesized that other group members would respond more positively to minority opinions during face-to-face discussion. This is because those offering the opinion would have more social presence, so that other members would pay more attention to them. McLeod et al. formed four-member face-to-face, anonymous computerized, and non-anonymous computerized groups to evaluate three companies available for acquisition by an imaginary investment company, based on information the researchers supplied the participants. One member of each group was purposely given information that differed from the other three group members. Consistent with their thinking, the researchers found the anonymous computerized groups to result in the most minority comments but also the most negative reactions to those comments by other group members. The highest number of positive reactions to minority comments and, probably as a consequence, the greatest individual opinion change occurred in the face-to-face groups. 
Consensus 

In general, computerized groups find it harder to reach a consensus than face-to-face groups. This might be as a result of the more equal participation in computerized groups. As we discussed earlier, equal participation inhibits a group's ability to form a stable role structure. Without a clearly dominant member or two directing the group, consensus is harder to reach. 
Again, however, there are complications. As discussed earlier, social presence theory implies that the effects of computerized message exchange should be less for tasks with objectively correct answers than for other types of tasks. Hiltz, Johnson, and Turoff (1986) asked five-member groups to decide either a survival-game accuracy problem or a human relations quality task. When working on the accuracy task, consensus was almost as great on computer as it was face-to-face. When working on the quality task, all eight of the face-to-face groups reached consensus, whereas only one of the eight computerized groups did. 

Task and Maintenance Activity 
It is probably the case that, at least for groups that are learning how to use computerized media, discussion is more task-oriented and less maintenance-oriented. In the Hiltz et al. study just mentioned, the researchers used Bales's coding scheme to content analyze the messages that members sent one another. They found the face-to-face groups to make about twice as many positive maintenance-oriented messages as the computer groups did. 
Another area in which computer groups seem to behave differently than face-to-face groups is negative maintenance behaviors. Social presence theory would hypothesize that both positive and negative maintenance behaviors would be lower in computer groups than in face-to-face meetings. Hiltz et al.'s findings for positive maintenance behaviors are consistent with this prediction. It is clear, however, that social presence theory is wrong about negative maintenance behaviors. People in computerized groups are more negative than people in face-to-face circumstances. A study that showed this came from Siegal, Dubrovsky, Kiesler, and McGuire (1986). In the study, three-person groups worked on choice dilemmas, either face-to-face or via computers. The researchers found that the computer groups made many more negative statements than the face-to-face groups. Their negative behaviors included swearing at and insulting one another. This type of behavior has come to be called flaming. 
It seems that flaming is likely to occur when group members are anonymous, so that the person who receives their flames has no way of knowing who sent them. A finding by Jessup, Connolly, and Tansik (1990) supports this possibility. Their research again compared anonymous computer conferencing with signed conferencing. They discovered that, when compared with the other participants, members in the anonymous groups made many more critical comments. 
One must not, however, overemphasize the importance of these findings. Even in computerized groups, flaming comprises no more than two or three percent of the total group interaction. 

Changes Over Time 
One reason that computerized groups are different than face-to-face groups is that computerized groups are often unfamiliar with their communication medium. This implies that as group members become more experienced in using computers to interact, their process and output should eventually become more equivalent to that of face-to-face groups. 
To test this idea, Hollingshead, McGrath, and O'Connor (1993) placed participants in three-or four-member groups that performed a variety of tasks across a 13-week semester, one task per week. For the first two weeks, face-to-face groups performed better than computerized groups, but for the next month there was no difference between communication media. During the seventh week, groups traded media; the previous face-to-face groups started using computers and the previous computer groups started working face-to-face. Once again, the newly-computerized groups performed worse for two weeks, after which there was no difference. Group member satisfaction paralleled task performance; lower for beginning computer groups, but no lower for experienced computer groups. 
Another area in which computer and face-to-face groups become more similar over time is in the proportion of task and maintenance comments. In several studies and essays, Walther has claimed that, even on computer, people have as great a desire to exchange maintenance information as they do face-to-face. However, people are unable to satisfy this desire at the beginning of their experience as members of computerized groups. Instead, members of new computerized groups concentrate on task information. These people often unfamiliar with computer conferencing. Further, it takes more time to type than to speak. For both of these reasons, members of new computer groups seem to feel that they need to concentrate their effort on task work. However, if the group stays together long enough, the rate of maintenance-relevant discussion will eventually increase to the level of face-to-face interaction. Walther's research results are consistent with these ideas, and he has found further support in reviews of other researchers' work (see Walther, Anderson, & Park, 1994). 
Emotional Content of Electronic Communication
Walther's research has important implications for the examination of the emotional content of computerized communication. Social presence theory leads to the idea that people will be less emotional when communicating on computer than when interacting face-to-face. The implication is that something inherent in computers causes this. They behave like an "informationally poor" medium. Emotional messages are absent because that is the nature of the medium. 
It may be true that members of decision making groups tend to be more task- and less maintenance-oriented when using computer conferencing. If this is the case, however, it may be limited to the decision-making situation. When researchers look at other circumstances in which people communicate by computer, the findings change. For instance, when people use computer networks to exchange personal "electronic mail," maintenance information is as great as face-to-face. Rice and Love (1987) examined six weeks of electronic mail messages that passed through a nationwide public system. Using Bales's coding scheme to analyze these messages, they discovered that 28 percent of the messages fit into Bales's categories as positive maintenance statements. This percentage is as high as Bales found when he analyzed face-to-face decision-making groups. 
The implication of these findings is that nothing inherent in computers leads to an absence of emotion in computer mediated groups. Clearly, one can communicate emotions electronically. In fact, people often go out of their way to add emotional information to electronic mail. Nonverbal codes for emotional information have become standardized among electronic mail users. For example, WRITING IN CAPITAL LETTERS means that the computer user is angry. Often, people who receive messages in capital letters will admonish the sender for yelling. Other nonverbal codes in common usage include a colon, a dash, and a closed parenthesis to symbolize happiness, as the smiling face below shows: 
:-)
In short, when people exchange personal messages, they will satisfy their maintenance needs even when they have to use "informationally poor" media. 
SUMMARY
Structures are often imposed on groups that form within organizations. One type of imposed structure occurs when who can communicate with whom in a group is restricted. We call these structures "imposed group networks." 
Scientists have found that group members have different roles in the flow of communication. They may be in the middle of the communication network, as central members, or they might be toward the outside, as peripheral participants. 
Groups as a whole are affected by how the communication flow is arranged. Groups with an unequal flow of communication, in which only a few members have greatest control over communication, are called centralized groups. An army might be an example of such a network. The army gives only a few people the right to talk to anyone, any time. In contrast, diffused groups allow their members more equal positions. For example, a circle of friends talking together probably would let all members talk equally. 
Experiments have shown that centralized groups perform better than diffused groups when they work on tasks that require only the exchange of information among members. An example might be a task that requires group members to seek a common symbol. Centralized groups, however, do not do as well with tasks that also require the manipulation of information (for example, working together on an arithmetic problem). In these cases, diffused groups perform better. 
In the maintenance realm, centralized groups tend to have a clearer power structure than diffused groups. The more central members act as leaders, and other members perceive them that way. Also, central members of centralized groups are the most satisfied of all group members in both networks. Diffused group members, however, on the average, tend to be more satisfied with their individual jobs than centralized group members. 
Research has shown that all these differences between centralized and diffused groups diminish over many trials. 
In a second type of structure, group members exchange messages through communication media rather than face-to-face when they make decisions. Different media place different restrictions on the number of communication channels that group members can use when they send messages. For instance, closed-circuit television allows members both to see and to hear one another. Telephone systems, on the other hand, allow them to hear only each other. Media that use written or typed messages allow for circumstances in which group members can only see one another or in which they can neither see nor hear one another. These restrictions take away nonverbal information from group members. Nonverbal information can signal members' degree of liking, power, and attentiveness. 
Theorists have looked at what happens to groups when media restrict their communication channels. They have proposed that the overall effect is to lower "social presence." Social presence is the feeling among group members that they are communicating with people rather than with impersonal objects. The way that social presence affects group process and output seems to depend on the type of task that a group performs. For accuracy tasks, group maintenance is relatively unimportant. For these kinds of problems a group's amount of social presence apparently has little effect on group process and output. In other tasks, however, group maintenance is important, such as in conflict and negotiation. Social presence does seem to affect these types of tasks. When groups with low social presence work on these tasks, participation becomes more equal, discussion content becomes more task-oriented, and cooperation lowers, relative to other groups. 

More and more groups are using computer conferencing to make decisions. When people in separate locations make decisions through computers, they can neither see nor hear one another. This implies that groups that use computer conferencing should have low social presence. Many findings on this topic are consistent with social presence theory. For example, the use of computer conferencing generally leads to more equal participation and influence among group members and more difficulty reaching group consensus. In addition, group discussion via the computer conference is probably low in maintenance statements and high in task focus. However, when people exchange personal messages by computer, their statements are often as maintenance-oriented as face-to-face interaction would be. This implies that social presence theory is wrong to presume that electronic media inherently leads to task-oriented behavior. Further, when groups experienced at computer conferencing, their performance becomes similar to face-to-face groups.