An investigation into the measurement invariance of the performance index
Date
2006-12
Authors
Dunbar-Isaacson, Hazel
Journal Title
Journal ISSN
Volume Title
Publisher
Stellenbosch : University of Stellenbosch
Abstract
The leadership-for-performance framework designed by Spangenberg and Theron (2004) aspires
to explicate the structural relationships existing between leader competency potential, leadership
competencies, leadership outcomes and the dimensions of organizational unit performance. The
Performance Index (PI) and Leadership Behaviour Inventory (LBI) comprise the leadership-forperformance
range of measures. The PI was developed as a comprehensive criterion measure of
unit performance for which the unit leader could be held responsible. The basic PI structural
model has been developed to explain the manner in which the various latent leadership
dimensions measured by the LBI affect the eight unit performance latent variables that are
assessed by the PI. Although preliminary research suggests the basic PI structural model could be
refined, continued research in this regard can only be justified if the basic PI measurement model
is shown to be measurement invariant across independent samples from the target population. As
part of ongoing research of the leadership-for-performance range of measures, this crossvalidation
study investigated the extent to which the PI measurement model may be considered
measurement invariant across two independent samples from the same population. Two samples
were collected through non-probability sampling procedures and included 277 and 375 complete
cases after imputation by matching. Item analysis and dimensionality analysis were performed on
each of the PI sub-scales prior to the formation of item parcels. No items were excluded based
on item- and dimensionality analysis results. Two composite indicator variables (item parcels)
were created from the items of each sub-scale and were treated as continuous variables in the
subsequent statistical analyses. Structural equation modelling, using robust maximum likelihood
estimation, was used to perform a confirmatory first-order factor analysis on the item parcels for
each sample. The measurement model was fitted to both samples independently and close fit for
each sample was established. The measurement model was cross-validated using a progressive
series of measurement invariance tests. Results indicated the PI measurement model did not
display full measurement invariance across the two samples although it did cross-validate
successfully under the configural invariance condition. Statistically significant non-equivalence
was found to exist in both the measurement error variances and the factor covariances (p<0,05),
although the p<0,05 critical value was only narrowly surpassed in both cases. The measurement
model did, however, display metric invariance across the samples as no significant differences
were found between the factor loadings, suggesting the content of each item is perceived and
interpreted in a similar manner across samples from the target population. When considered in
combination, these results may be viewed as quite satisfactory as they indicate that themeasurement model does not appear to vary greatly when fitted to data from the two samples. As
this study has established at least metric invariance of the PI, it therefore provides some basis of
confidence for proceeding with subsequent research aimed at establishing the structural
invariance of the basic PI structural model and eventually research that links the leadership
behaviour to work unit performance as measured by the PI. Limitations of this study are
discussed.
Description
Thesis (MComm (Industrial Psychology))--University of Stellenbosch, 2006.
Keywords
Dissertations -- Industrial psychology, Theses -- Industrial psychology, Organizational effectiveness -- Measurement, Performance -- Measurement, Teams in the workplace -- Evaluation, Analysis of variance