Factor structure and measurement invariance of the Basic Psychological Needs Scale in three South African samples: A bifactor exploratory structural equation modelling approach.

Abstract

The Basic Psychological Needs Scale (BPNS) is still being used but validation studies that applied confirmatory factor analysis (CFA) revealed that the scale has inadequate psychometric properties. CFA is based upon restrictive statistical assumptions that may result in biased parameter estimates. There are statistical developments that overcome these limitations. This study explored the factorial validity of the scale in three South African student samples who completed the English (n = 326), Afrikaans (n = 478), or Setswana (n = 260) version of the BPNS. CFA, bifactor CFA, exploratory structural equation modelling (ESEM) and bifactor ESEM were applied to the data. The three-factor bifactor ESEM model yielded the best fit, but model fit was inadequate for the English and Setswana versions, and almost adequate for the Afrikaans version. After removal of problematic items based on substantive reasons, high modification indices, and high expected parameter change values, reduced bifactor ESEM models displayed adequate fit. The general factor showed sufficient reliability scores for all language versions. Subscales exhibited insufficient reliability scores, except for the Competence and Relatedness subscales of the BPNS-Afrikaans. A reduced three-factor bifactor ESEM model was partially metric invariant for the English and Afrikaans groups. The BPNS-Afrikaans showed potential for use, but alternative measures of basic psychological needs should be considered for the English and Setswana groups in the current context. The cross-cultural application of basic psychological needs in a South African context is questioned. An emic approach to exploring and conceptualising basic psychological needs in African contexts is recommended.