Investigation of the Humm Wadsworth Temperament Scale : revision, development and application : this thesis is presented in partial fulfilment of the requirements for the degree of Master of Arts in Psychology at Massey University, New Zealand
The present investigation examines the psychometric properties of a measure of temperament, the Humm Wadsworth Temperament Scale (Humm). To this end, participants (n = 27,245) completed the Humm questionnaire as part of either a recruitment and selection process initiated by a prospective employer, a promotion and development assessment initiated by their current employer, or career guidance advice sought of their own volition. Quantitative theoretical analysis based on Thurstone's method of paired comparisons and conceptual analysis by Humm experts and users were utilised for both the single-loading items for each of the seven components of the Humm, as well as the remaining multi-loading items. Thurstone's method was used to rank order items conceptually from 'best' predictor to 'worst' predictor of a certain component, which in turn were used to identify which items should remain in the Humm and which items should be discarded. The conceptual judgments generated by Humm experts and users, followed by confirmatory factor analysis, were used to increase the validity of the Humm through revising the set of items in the version of the Humm currently in use. The study concludes with a discussion of issues surrounding psychometric test revision, applicability of the Humm to the wider community including culturally diverse populations, as well as suggestions and recommendations for future research in this area.