The first part of this thesis comprises a review of some of the extensive literatures on locus-of-control and task motivation. The exercise reveals that, while the locus-of-control construct has received considerable support, no satisfactory explanation of its functional characteristics as a motivational variable is available. This appears to be because locus-of-control is not a unitary construct. Previous analyses have depended almost entirely on existing measurement scales, notably Rotter's I-E Scale. In this thesis, the theoretical component is a conceptual analysis of the locus-of-control construct, and the empirical component consists of the construction and testing of a set of interlocking scales, which assess the relative importance for common events of six loci of control. The task is specially defined as a unit of behaviour which is further analysed in terms of preparatory, decisional and operating phases. Locus-of-control is construed as the subjective relationship between effort input and performance output in a task, and this relationship is further differentiated into effort-effectiveness, task competence and range of uncertainty components. These parameters are considered in conjunction with the arousal value of the relationship between performance and satisfaction, and the inhibitory effect of effort, in a model of task behaviour which unites locus-of-control, decision-making and motivation theory. Differences between Africans and Europeans are predicted for the structure of control beliefs, and a cross-cultural study is described which used the I-E Scale and the author's "A-C Scales". The results indicate acceptable levels of reliability and independence for the A-C Scales, and reveal cross-cultural variation in the meaning of external control. The theoretical implications are outlined. Both the model and the design of the instrument appears to make a significant impact on the theoretical and methodological problems in the area. Various practical applications are discussed.<p
