SOCIAL NETWORK TIES, TRANSACTIVE MEMORY,

AND PERFORMANCE IN GROUPS

Jay Lee, University of KansasDan Bachrach, University of AlabamaKyle Lewis, University of Texas

Overview of the study• We integrate research lines in the areas of Social Capital

theory and Transactive Memory Systems (TMS) theory to argue that groups with certain information network structures are more likely to develop a TMS and achieve high performance.

• Combining TMS theory with Social Capital Theory allows for:– Nuanced understanding of how information networks of collaborating

individuals can affect group performance– What types of network structures produce these effects

• Findings: – High reciprocity structures reduce TMS and performance– Structures with axis members increase TMS and performance

Social capital and TMS• Social capital: the sum of the actual and potential resources

embedded within, available through, and derived from ties within a network of social relationships (Bourdieu, 1986; Burt, 1992). – Research: structure of social relationships affects individual

and collective outcomes

• TMS: The shared division of cognitive labor with respect to learning, remembering, and communicating information (Hollingshead, 2001; Wegner, 1987)

– Research: transactive processes affect individual and collective knowledge, group performance

Structure of information network

1. Reciprocity– Network reciprocity is defined as the degree to which

dyadic exchanges between any two team members are characterized as reciprocal (Wasserman & Faust, 1994).

2. Axis members

Reciprocity: Antecedents & Outcomes

• Task interdependence creates need for mutual adjustment and coordination: high task interdependence reciprocal interactions and information sharing between members.– Hypothesis 1a: Task interdependence has positive effects

on network reciprocity.• Increased information sharing higher group performance

– Hypothesis 1b: Network reciprocity is positively related to group performance.

Structure of information network1. Reciprocity2. Axis members

– We define axis member as a team member having outgoing ties to two remaining members between whom sequential or reciprocal ties exists.

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Axis Members: Antecedents & Outcomes• Task interdependence creates need for coordination and

distribution of task-relevant information; axis members pass relevant information, coordinate transactions between others, facilitate consensus.– Hypothesis 2a: Task interdependence has positive effects

on the number of axis members within a group.• Axis member monitors, coordinates, facilitates information

transfer; greater focus on group-level information exchange.– Hypothesis 2b: The number of axis members within a

group is positively related to group performance.

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TMS theory

• TMSs develop as:– Members develop an understanding of who knows what (as members

interact, members’ understanding becomes similar, “shared”)– Members choose to learn about some domains and not others

(produces specialized individual knowledge, differentiated group knowledge)

• TMS processes create:– Individual specialized knowledge– Group-level knowledge (knowledge shared by all

members)

TMS theory and network structure: Axis Members

• Shared understanding of who knows what is essential to TMS triadic network structures more likely to help a TMS develop.

• Axis members can help teams to:• Form agreements regarding the location of specialties• Avoid repeating and redundant information requests/exchange• Build a shared sense of the location of the knowledge

– Hypothesis 3: The number of axis members within a group is positively related to TMS.

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TMS theory and network structure: Reciprocity

• Without a group-level understanding of who knows what, dyadic reciprocal exchanges can lead to redundant information exchange impede the development of TMS

• Multiple dyads exchanging some of the same (i.e., overlapping) task-relevant information.

• After controlling for the benefits of the triads, – Hypothesis 4: Network reciprocity is negatively related to

TMS.

TMS as mediating force

• Previous research supports the notion that teams with a more developed TMS tend to achieve objectively higher levels of performance than teams with less well developed TMSs (Akgun, Byrne, Keskin, Lynn, & Imamoglu, 2005; Lewis 2004; Zhang et al., 2007)

– Hypothesis 5a: The relationship between the number of axis members within a group and group performance is mediated by TMS.

– Hypothesis 5b: The relationship between reciprocity and group performance is mediated by TMS.

Conceptual Model Linking Task Interdependence, Structure Variables, Transactive Memory, and

Team Performance

Task Interdependence

Number of Axis Members

Network Reciprocity

TransactiveMemory System

Team Performance

Experiment

• Subjects– 330 participants organized into 110 three-person teams – Undergraduate students– 75% juniors and 17% seniors– 88% Caucasian; 61% female

• $300 dollar award cash awards to increase group goal interdependence (Van Der Vegt, Emans, & Van De Vliert, 2000)

Experiment

• Group task• Compensation allocation task (Rico and Cohen, 2005)

– Groups of participants recommend a merit increase for the 42 employees of a fictitious company described at the outset of the experiment.

– To determine employees’ ratings, weight the rating, calculate the total weighted score, and recommend a final merit increase.

• Manipulation– High vs. low task interdependence (MH=6.39; ML=5.21, p < .01)

Measures• Social capital measure

– “Please indicate how often this person has provided you relevant information in the course of completing your part of the group task (1=at times, 2=often, 3=very often, 0 = never) ”

– Axis member was counted from a sociogram– Reciprocity (arc measure) from UCINET

• Transactive memory system– Lewis (2003)

• Group performance: compare group decisions to correct (optimal) decisions.

RESULTS: Significant Paths Found in the Structural Model

Analysis of direct and indirect effects shows TMS mediates effects

Number of axis members

Reciprocity of information

network

Task

interdependence

Transactive

Memory

System

Team

performance

.32 ***

.15

.35 ***

.44 ***

-.23 *

.30 **

Summary• Task interdependence: driver of social capital

• Number of Axis members• Reciprocity

• Social capital (number of axis members) predicted team performance; reciprocity did not.

• TMS framework uncovered differences that depended on network structure type– Teams with axis members (who facilitate group-level information

exchange) developed TMS– Teams with a mode of reciprocating information only at the dyadic

level did not develop TMS• The presence/absence of TMS further predicted team performance

Contributions

• TMS literature– Network structure can be a precursor of TMS– Third parties (such as the axis member in our study) can

help build a TMS• Social capital/network

– Different effects from dyadic (highly reciprocity networks) vs. triadic (axis member) network structures

• Network member interdependencies lead to the development of certain forms of network structure, and TMS explains how different structures affect collective outcomes.

Direct, Indirect, and Total effects of Task Interdependence on the development of TMSa,b,c,d

Effects of network variables on group performance Effect sizeb

 

95% Confidence Intervald

Lower bound   Upper bound

Total effect of network reciprocity on group performance .01 (.10) -.184 .204

Direct effect .10 (.10) -.105 .296

Mediating effect through TMSc (Test of H5a, HO: = 0) -.08 * (.06) -.237 -.002

Total effect of number of axis members on group performance .28 ** (.09) .097 .453

Direct effect .12 (.12) -.114 .346

Mediating effect through TMSc (Test of H5b, HO: = 0) .16 * (.08) .028 .353

                     

a. *** p < .001, ** p < .01, * p < .05 (two-tailed)b. The values in the parentheses are standard errors.c. To test the overall mediating effect of social network variables, a bootstrapping method of mediating test (Shrout and

Bolger, 2002) was conducted (HO: = 0) (The focal network variable TMS Group performance). d. The estimation of confidence interval was based on the bias-corrected percentile method

Estimated Marginal Means of TMS and Team Performance in Teams with Four Different

Numbers of Axis Members

The plot on the left is based on Model 2 of Table 5, and the plot on the right is based on Model 2 of Table 6.

Supplementary materials

  MeanStd. Dev. 1   2   3   4   5  

1. Team performance 0.57 0.14                    

2. Transactive memory system 5.27 0.58 0.35 ***                

3. Number of axis members 1.17 1.14 0.33 *** 0.36 ***            

4. Reciprocity of information network 0.6 0.4 0.14   -0.05   0.36 ***        

5. Task interdependence condition 0.5 0.5 0.23 * 0.22 * 0.33 *** 0.16      

6. Social familiarity 2.84 2.35 0.06   0.12   0.14   0.08   0.06  

Correlations

Measures• Group performance measure

– Modified version of Rico and Cohen (2005)

– i = profile of employee i among the 42 employees in the activities

– Ai = actual team evaluation score for employee i

– Ci = correct evaluation score for employee i

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ii CAP