1. SOCIAL NETWORK TIES, TRANSACTIVE MEMORY, AND PERFORMANCE IN GROUPS Jay Lee, University of Kansas Dan Bachrach, University of Alabama Kyle Lewis, University of Texas

2. 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

3. 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

4. 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

5. 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.

6. Structure of information network 1.Reciprocity 2.Axis members – We define axis member as a team member having outgoing ties to two remaining members between whom sequential or reciprocal ties exists.

7. 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.

8. 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)

9. 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.

10. 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.

11. 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.

12. Conceptual Model Linking Task Interdependence, Structure Variables, Transactive Memory, and Team Performance Task Interdependence Number of Axis Members Network Reciprocity Transactive Memory System Team Performance

13. 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)

14. 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 (M H =6.39; M L =5.21, p <.01)

15. 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.

16. 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 **

17. 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

18. 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.

20. Direct, Indirect, and Total effects of Task Interdependence on the development of TMS a,b,c,d Effects of network variables on group performanceEffect size b 95% Confidence Interval d 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 TMS c (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 TMS c (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

21. 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.

22. Supplementary materials Mean Std. Dev.1 2 3 4 5 1. Team performance0.570.14 2. Transactive memory system5.270.580.35 *** 3. Number of axis members1.171.140.33 *** 0.36 *** 4. Reciprocity of information network0.60.40.14 -0.05 0.36 *** 5. Task interdependence condition0.5 0.23 * 0.22 * 0.33 *** 0.16 6. Social familiarity2.842.350.06 0.12 0.14 0.08 0.06 Correlations

23. 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