Abstract
A major problem in shiftwork research has been the lack of uniform measuring procedures across studies. The Standard Shiftwork Index (SSI) contains a battery of self-report questionnaires which was developed to address this need. The objectives of this study included examining the cross- cultural applicability, internal consistency, and construct validity of the SSI scales for a predominantly Afrikaans-speaking sample of 728 train drivers and to provide normative distribution statistics for this sample. Factor analytic results and the correlations between the various scales supported the constnuct validity of the SSI scales. Means obtained on the scales were compared with means obtained for British shiftworkers and non-shiftworkers. The inclusion of job satisfaction and involvement scales, and scales to assess sleep variables appeared to augment an outcome- based theoretical model proposed by the compilers of the SSI. It was concluded that the SSI is a useful research tool for use with shiftworkers, but that further development of some of the scales is advisable.