The measurement invariance and measurement equivalence of the sources of work stress inventory (SWSI) across gender groups in South Africa

The primary goal of an organisation, in a capitalistic system, is the maximisation of profit. The task of the human resource function in organisations is to affect the work performance of working man to the advantage of the organisation and in a manner that adds value to the organisation. The management of employee wellbeing/psychological health is one of the human resource interventions with which the human resource function pursues this objective. It is imperative for organisations to be aware of, and sensitive to, negative factors in the workplace, such as occupational stress, that influence employees’ health and wellbeing and have a significant effect on job satisfaction and performance (Hamidi & Eivazi, 2010). Prevailing stress levels need to be monitored regularly if escalating stress levels are to be detected in time to prevent serious personal and organisational problems from developing. The Sources of Work Stress Inventory (SWSI) is an instrument developed in South Africa specifically for this purpose (De Bruin & Taylor, 2005). The inappropriate use of occupational stress assessments across genders can seriously jeopardize the extent to which occupational stress assessments, and the decisions based on them, achieve their intended objectives. In order to avoid making widespread generalisations and untested assumptions which will eventually do a disservice to the field of psychology, the absence of measurement bias (i.e. invariance and equivalence) should be demonstrated instead of simply assumed (Van de Vijver & Tanzer, 2004). Establishing the measurement invariance and equivalence of an instrument across groups should be a prerequisite to conducting substantive cross-group comparisons (Dunbar, Theron & Spangenberg, 2011). It is imperative to empirically ascertain whether the instruments that are used are free of cultural, language, gender, age and racial bias, not only because it is prohibited by the Employment Equity Act 55 of 1998, but also as it is in the interest of good workmanship. Bias is indicated as nuisance factors that threaten the validity of cross-group (cultural) comparisons (Van de Vijver & Leung, 1997). These nuisance factors could be due to construct bias, method bias and/or item bias. Due to the importance of the decisions made, it would seem essential that the information provided by test results apply equally across different reference groups. In this study the specific measurement invariance and equivalence sequence of tests set out by Dunbar et al. (2011) was used to answer a sequence of research questions that examine the extent to which the SWSI multi-group measurement model may be considered measurement invariant and equivalent or not, and to determine the source of variance if it existed (Vandenberg & Lance, 2000). Upon investigating the measurement model fit of the SWSI, the results indicated that support was found for the hypotheses that the measurement model fits the data of both gender samples independently. Furthermore, support was found for the configural and weak invariance model. However, due to not Stellenbosch University https://scholar.sun.ac.za