A Multilevel Model Analysis with GRAND

Guang Ying Mo Department of Sociology, University of Toronto

SUNBELT, Hamburg, May 23, 2013 1

Introduction Literature review Research questions Method Findings Conclusion

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Growth of Multidisciplinary Collaboration (MDC).

Shift from traditional research organizations to networked research.

Top-down arrangement of networked research How does the top-down arrangement of MDC

shape real multidisciplinary interactions among resarchers?

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Social capital theory on diversity 1. Diversity at the dyadic level (Lin 1999;

Erickson 2003) 2. Diversity at the network level (Reagans. 2004) Two types of diversity: Compositional Diversity: the degree of variation among the attributes of network members, e.g. gender, ethnicity, age at the network level. Interactional Diversity: the extent of actual boundary-spanning interactions at the individual level.

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Rational choice theory (Becker 1974) 1. Preference (of compositional diversity) 2. Action (of interactional diversity) 3. Rewards (e.g. status, productivity) A multilevel model of diversity including

compositional diversity at the project level, interests in MDC and interactional diversity at the individual level.

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Compositional Project-Level Diversity H3 H1 H5 Interests H2 Interactional In MDC Diversity H4 Status Individual-Level

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H1: The greater compositional diversity a project exhibits, its members show the greater interactional diversity.

H2: The more researchers want to involved in multidisciplinary collaborations, the greater their interactional diversity.

H3: Compositional diversity moderates the relationship between rationale and interactional diversity. When compositional diversity increases, those who have higher rationale for multidisciplinary collaborations show greater interactional diversity.

H4: The higher researchers status, the lower their interactional diversity.

H5: When compositional diversity increases, those who have higher status have lower interactional diversity.

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44% of NIs are working with 3 projects. 24% of NIs are working with more than 3 projects. 75% of CRs are working with 1 projects

3

10

18

7

3

45

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2

1

0

1

2

3

4

5

NI

CR

Individual N=144, Project N =144

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0 5 10 15 20

P1

P3

P5

P7

P9

P11

P13

P15

P17

P19

P21

P23

P25

P27

P29

P31

CS

ER

ICM

MDA

HM

SS

PRF

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Online survey on collaborators’ social networks in GRAND (N=101)

1. Rationale (want-to-meet) 2. Interaction (comm., support, work) 3. Attributes (status, age, gender, location) GRAND roster Compositional diversity of projects Heterogeneity index Blau (1977) 1-∑𝑝𝑝𝑖𝑖2 where p is the proportion of the number of people in the ith disciplinary category. 11

P1 P2 P3 P4 P32 r1 r2 r3 r4 r5 r6 r7 r8 r144

𝑦𝑦𝑖𝑖=𝛽𝛽0+𝛽𝛽1𝑥𝑥1𝑖𝑖+𝛽𝛽2 ∑ 𝑤𝑤𝑗𝑗,𝑖𝑖(2)

𝑗𝑗∈𝑝𝑝𝑝𝑝𝑝𝑝𝑗𝑗𝑝𝑝𝑝𝑝𝑝𝑝(1) 𝑥𝑥2𝑗𝑗(2)+

∑ 𝑤𝑤𝑗𝑗,𝑖𝑖(2)

𝑗𝑗∈𝑝𝑝𝑝𝑝𝑝𝑝𝑗𝑗𝑝𝑝𝑝𝑝𝑝𝑝(1) 𝑢𝑢𝑗𝑗(2)+𝑒𝑒𝑖𝑖

𝑢𝑢𝑗𝑗

(2)~ 𝑁𝑁 (0,𝜎𝜎𝑢𝑢(2)2 )

𝑒𝑒𝑖𝑖~𝑁𝑁(0,𝜎𝜎𝑝𝑝2)

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Mean S.D. Individual level variable Dependent Variable

Interactional Diversity 0.31 0.22 Independent Variable

Interests in MDCs 0.46 0.22 Age 46.59 8.98 Role in GRAND 0.41 0.49 Academic ranking 2.03 0.82 GIndex 51.74 60.46

Control Variable Gender 0.27 0.45 % of researchers in same city 0.10 0.06

Project-Level Variable Compositional Diversity 0.51 0.27 Note: Unless otherwise noted, individual N=101, Project N=32 13

Model 1 Model 2 Model 3 Model 4 Intercept -0.004 -0.129 -0.359 -0.356 Individual level variable

Interests in MDCs 0.657*** 0.644*** 0.749*** Age 0.064 0.060 0.064 Role in GRAND .217** 0.224*** -0.026 Academic ranking 0.010 0.014 0.015 GIndex 0.058 0.074 0.058 Gender 0.269ᶧ 0.277ᶧ 0.227 % of researchers in same city 0.563 0.626 0.743

Project-Level Variable Disciplinary Diversity 0.456ᶧ 0.496ᶧ

Cross-Level Interactions

Compositional DiversityXRationale -0.201 Compositional DiversityXStatus 0.517ᶧ

Variance Estimates Group Variance 0.342*** 0.048*** 0.392*** 0.026***

Individual Variance 0.732*** 0.288*** 0.284*** 0.280*** Individual N=101, Project N=32

ᶧp < .1 (one-tailed test), *p < .05; ** p<.01; *** p<.001 (two-tailed tests) 14

Compositional diversity fosters interactional diversity (H1 supported).

Researchers who are more willing to be involved in multidisciplinary collaborations show greater interactional diversity. (H2 supported)

Researchers in a higher position in GRAND show higher interactional diversity. (H4 refuted)

Compositional diversity moderates the effects of researchers’ roles on interactional diversity. In projects of high compositional diversity, those in higher positions indicates greater interactional diversity. (H5 refuted) 15

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