to test this hypothesis is outlined in table 9.15. The regression model accounts for 25 % o f the variance in new product development capability and is significant (F 2 ,4 5= 7.52,
when the effects o f efficiency are removed. Effectiveness appears to be more important predictor o f new product development capability than efficiency.
Table 9.15 Multiple Regression of New Product Development Capability on Effectiveness and Efficiency I n d e p e n d e n t V a r i a b l e s B e ta t R 2 R 2a d j F D f .2 5 .2 2 7 .5 2 * * 2 , 4 5 E f f e c t iv e n e s s .3 9 2 .5 4 * E f f ic ie n c y .1 6 1 .0 2 * p < .0 5 , * * p < .0 1
9.9
Tests of Mediation
Two hypotheses predicted mediated relationships: hypothesis 11 predicted that social interaction (quality and quantity) and team tacit knowledge w ill be mediated by the development o f a transactive memory system and hypothesis 14 predicted that the relationship between social interaction (quality and quantity) and transactive memory w ill be mediated by psychological safety.
To test these hypotheses a four stage analysis was conducted to test whether the three conditions for mediation were satisfied: (1 ) the independent variable significantly predicts the dependent variable, (2) the independent variable predicts the proposed mediator, and (3) the mediator is a significant predictor o f the dependent variable, when we control for the independent variable (4) I f the mediator is a complete mediator o f the relationship between the independent variable and the dependent variable, the effect o f the independent variable when controlling for the mediator, should be zero (Baron & Kenny, 1986), or at least not significant (M iles & Shevlin, 2001). The results o f the mediation analyses for hypotheses 11 and 14 are shown in tables 9.16 and 9.17 respectively.
Table 9.16 M ediation A nalysis for T ransactive M em ory
Conditions to Demonstrate Mediation in Independent
Three Stages variable B t P R2
Stage 1
Does quality o f social interaction Quality o f social .59 3.41 <.01 .20
significantly predict team tacit knowledge? D oes quantity o f social interaction
significantly predict team tacit knowledge?
interaction Quantity o f social interaction
.02 1.15 >.05 .03
Stage 2
Does quality o f social interaction Quality o f social 1.40 5 2 2 < 0 0 1 .37
significantly predict transactive memory (composite score)?
interaction
Stages 3 & 4
D oes transactive memory predict team tacit knowledge when quality o f social
Transactive memory Quality o f social .02 .56 .21 2.55 >.05 <.01 .20
interaction is controlled? interaction
In stage 1, team tacit knowledge w as regressed on quality o f social interaction and quantity o f social interaction, respectively. Q uality o f social interaction satisfied the first condition for mediation (B = .59, p<.01), quantity o f social interaction did not, and so was not included in further mediation analyses. Furthermore, it is noted that quality social interaction accounts for 37% o f the variance in transactive memory. In stage 2 the second order factor o f composite transactive memory were regressed on quality o f social interaction. In the final stage, team tacit knowledge was regressed on transactive memory, w hile controlling for quality o f social interaction. The mediators ceased to exert a significant influence on team tacit knowledge when quality o f social interaction was controlled. Therefore, the third condition for mediation was not met. Therefore social interaction (quality and quantity) and team tacit knowledge are not mediated by transactive memory.
Table 9.17 Mediation Analysis for Team Psychological Safety
Conditions to Dem onstrate M ediation in Independent
Four Stages variable B t _ P R2
Stage 1
Does quality o f social interaction Quality o f social 1.40 5.22 < , 0 0 1 .37
significantly predict transactive memory
(composite score)?
Does quantity o f social interaction
interaction
Quantity o f social .16 5.71 < 0 0 1 .40
significantly predict transactive memory? interaction Stage 2
Does the quality o f social interaction Quality o f social 1.08 3.52 < 0 0 1 .21
significantly predict psychological safety? Does the quantity o f social interaction significantly predict psychological safety?
interaction Quantity o f social interaction
. 1 0 2 . 8 < 0 1 .15
Stages 3 and 4
Does psychological safety predict
transactive memorywhen quality o f social interaction is controlled? Psychological safety Quality o f social interaction .50 . 8 6 4.21 3.42 < 0 0 1 < 0 1 .58
Does psychological safety predict
transactive memorywhen quantity o f social interaction is controlled?
Psychological safety Quantity o f social interaction ,51 . 1 1 5.32 4.64 < 0 0 1 < 0 0 1 .64
In stage 1 the second order factor o f transactive memory was regressed on quality o f social interaction and the quantity o f social interaction respectively. Q uality o f social interaction and quantity o f social interaction were found to be significant predictors o f transactive memory, satisfying condition one for mediation.
In the second stage, psychological safety was regressed on the quality o f social interaction and the quantity o f social interaction respectively. Both quality and quantity o f social interaction were significant predictors o f psychological safety. The second condition for mediation was met.
The third condition was assessed first for quality o f social interaction. Psychological safety was a significant predictor o f transactive memory (composite score), while controlling for quantity o f social interaction, satisfying the third condition for mediation. The amount o f mediation for transactive memory (composite score), was calculated by finding the difference in the slopes from stage 1 to stage 4, which was 1.40 - 0.86 = 0.54. The third condition is now assessed for quantity o f social interaction. Psychological safety was a significant predictor o f the independent variables, transactive memory, w hile controlling for quality o f social interaction, satisfying the third condition, for mediation. The amount o f mediation for transactive memory was calculated by finding the difference in the slopes from stage 1 to stage 4,
which was 0. 16 - 0.11 = 0.05.
However, psychological safety can only be viewed as a partial mediator since quality and quantity o f social interaction are still significant predictors o f transactive memory (composite score), but there was a reduction in effect due to psychological safety.
9.10 Post hoc Predictions with Transactive Memory First Order
Factors
The central hypotheses for the main model, were re-run, p o st hoc, with the first order factors o f credibility, specialisation and coordination.
9.10.1 Predicting Team Tacit Knowledge
To test the hypothesis that social interaction (quality and quantity) would predict tacit knowledge above and beyond transactive memory (hypothesis 24), the first order factors (specialisation, coordination and credibility) were entered together as control variables, in the hierarchical regression (step 1). Scores on the quality and quantity o f social interaction were entered in step 2. The results are presented in Table 9.18 and depicted in Figure 9.11.
The results in table 9.18 show that the first model entered in step 1 o f the first order factors specialisation, credibility and coordination an explain 24 % o f the variance and is statistically significant (F3, 4 4 = 4.62, p<,01). Around 30 % o f the variance in team
tacit knowledge is accounted for by all o f the variables combined in the fu ll model, w hich is statistically significant (F 5< 4 2 = 3.68, p<.01; see Figure 9.11). Quality and
quantity o f social interaction describe 6 % of variance in team tacit knowledge above
and beyond the first order factors and are not significant (AF = 3.71, p>.05).
None o f the beta weights were significant for the fu ll model, credibility, coordination, quality o f social interaction and team tacit knowledge were all significantly to related to one another (Table 9.7) but each is no longer significantly related to team tacit knowledge when the effects o f the others are removed. Indicating that the variables make a strong joint contribution in the model, but may underestimate the unique importance o f each variables.
Quantity o f social interaction was positively, though not significantly correlated with the criterion variable and has a negative beta weight. To include quantity o f social interaction in the model serves to suppress or discount scores on the other predictors of teams scored higher on team tacit knowledge because o f quantity o f social interaction rather than because o f their scores on coordination, credibility and quality o f social interaction. Specialisation does not significantly predict team tacit knowledge and is negative in direction, consistent with the zero-order correlation,
Table 9.18 H ierarchical R egression o f T eam T acit K n o w led g e on S p ecialisation, C redibility and Coordination and on Q uality and Q uantity o f S ocial Interaction
Independent variables Standardised beta weights
Stepl Step 2
D f
B t B t
Step 1: Control variables 3 , 4 4
Specialisation - .27 -1.86 - . 2 7 -1. 94
Credibility . 2 2 1.07 .26 1.13
Coordination .31 1.53 .12 .54