It is argued, in relation to the cross-cultural equivalence of personality measures, that of the three phases of test development namely construction, establishment of reliability and of validity, the second tends to receive too little attention. Accordingly, Rotter I-E Scale data from black and white students in Zambia and Rhodesia were compared with each other and with data collected in other countries. It is concluded that the Rotter I-E Scale is not a reliable instrument even for American groups; that responses may reflect manifest item content more than underlying cognitions about control; and that while locus-of-control seems a valuable and perhaps valid construct for cross-cultural personality and motivation research, we need better scales to measure reliability. s. Atr. J. Psychol. 1979, 9: 61 -66 Met betrekking tot die tussenkulturele ekwivalensie van persoonlikheidsmetinge, word dit aangevoer dat daar in die drie fases van toetsontwikkeling (konstruksie, betroubaarheidsbepaling en geldigheidsbepaling) te min aandag gegee word aan betroubaarheidsbepaling. Gegewens wat met behulp van die Rotter I-E Scale van swart en wit studente in Zamble en Hhodeale verkry is, is vergelyk. Vergelykings is ook get ref met gegewens wat in ander lande versamel is. Op grand van die bevindings word die gevolgtrekking gemaak dat die Rotter I-E Scale nie 'n betroubare meet instrument is nie -nie eens vir Amerikaanse groepe nie en dat waar die konstruk tokus-van-kontrole waardevol en moontlik geldig blyk te wees vir tussenkulturele persoonlikheidsen motiveringsnavorsing, daar tog 'n behoefte is aan beter skale om hierdie konstruk betroubaar te meet.