Organizational Behaviour Comportement Organisationnel

appropriate choice given the focus in this study on behavior similarity between pairs of actors andthe use of relationships to model social influence mechanisms. In addition, a problem with usingvariables computed from social network data (i.e., relationships between individual actors) inconventional statistical testing is dyadic auto-correlation and the resulting non-independence ofobservations. Krackhardt (1988) has shown the potential for conventional regression to estimatebiased parameters under such conditions. QAP confronts the autocorrelation problem by using anon-parametric test, which compares observed parameter estimates with a population ofcorresponding estimates produced from random permutations of the data. The significanceestimates for the results in Tables 2 and 3 correspond to the proportion of randomly computedparameter estimates that were as extreme as the observed parameter estimate and can beinterpreted in the conventional manner (Shah, 1998). In addition, as data about relationships werecollected only between members of the same work unit, all analyses were performed separately ineach unit. Inferences about the sample as a whole were then made using Rosenthal’s (1978) metaanalysisprocedure for combining results from different samples (see Krackhardt & Porter, 1986).ResultsRegression coefficients for all social influence effects are displayed in Tables 2 and 3.The general pattern of results support the predictions made in this study. Table 2 shows theresults for the social influence effects on Social Support, an interpersonal OCB. The top panel ofTable 1 shows that in three of the work units, the presence of a mutual expressive (i.e.,friendship) relationship between two actors was significantly associated with greater similarity inthe performance of these behaviors. Combining the results across the eight work units alsoyielded a significant effect of direct social influence on behavioral similarity (Combined Z = -2.95, p < 0.01). Panel 2 in Table 2 shows that indirect social influence between structurallyequivalent actors in the expressive network had no significant effect on the similarity of SocialSupport behavior (Combined Z = 0.97), although one work unit did exhibit a significantcoefficient. The lower two panels in Table 2 show the results for relationships in the instrumentalnetwork. The direct social influence effect of a mutual advice relationship on behavioralsimilarity was marginally significant (Combined Z = -1.57, p < 0.06). There was no evidence ofindirect social influence between structurally equivalent actors in the advice network (CombinedZ = 0.48).Table 2QAP Regression Coefficients for Social Influence on Social Support BehaviorVariable NameExpressive NetworkDirect InfluenceIndirect InfluenceInstrumental NetworkDirect InfluenceIndirect InfluenceUnit 1-0.18*0.02-0.180.10Unit 2-0.23*0.17 $-0.030.10Unit 30.03-0.060.14 $0.02Unit 4-0.050.41**-0.22*0.17*Unit 5Unit 6-0.07 -0.16*-0.30 $ -0.05-0.01 -0.08-0.30 $ -0.04Unit 7-0.10 $-0.10-0.11 $-0.11Unit 8-0.220.05-0.17-0.0159