To determine whether or not Employee Positive Attitudes (EPA) has a partial
mediation effect on the ML→JP relationship it is necessary to estimate a third
model (SEM 3b 2 ) in which there is no indirect effect (EPA→JP) on Job Performance
(JP). The structural coefficient values for the ML→JP path are now compared
between model SEM 3b 2 and the hypothesised model SEM 3b. In the constrained
model (SEM 3b 2 ) the value (effect size) for the ML→JP path is 0.422 while in the
hypothesised model (SEM 3b) this value is 0.262. When comparing the ML→JP
path between the constrained model (SEM 3b 2 ) with the hypothesised model,
because ML→JP is statistically significant in both models, but the parameter
estimate is reduced in size in the hypothesised model (0.422 in SEM 3b 2 and
0.262 in SEM 3b), we can conclude that partial mediation is supported (Hair et al.
2006 : 867).
7.6.1 Model 3 / Model 3b summary
Model 3 was specified and estimated and to test hypotheses H 1 to H 8 as illustrated
in Figure 7 - 15.
The three Employee Attitude constructs - Job Satisfaction (JS), Affective
Organisational Commitment (AOC) and Work Meaning (ME) – did not, however,
demonstrate satisfactory discriminant validity (i.e. they were found not to be
measuring distinct constructs). The model was re-specified with just one
Employee Attitudes construct and developed into the model (Model 3b) illustrated
in Figure 7 - 16.