Bibliography: leaves 123-136.Recognition of the need to develop black employees' interpersonal skills in order that they cope with the demands of the western business environment formed the backdrop to this study. The use of currently available self-report measures of assertiveness to assess behaviour change was questioned in terms of their psychometric properties and relevance to the black employee working in South African organisations. The aim of this study, therefore, was to develop a self-report instrument to measure assertiveness of black employees in work organisations. Another objective was the assessment of criterion-related validity. Information gathered from 12 in-depth interviews was used in the writing of new items and assisted in the modification of items from available self-report assertiveness measures. A preliminary questionnaire, consisting of 55 items was subsequently developed. After a number of changes, the questionnaire, consisting of a four-point Likert scale, was distributed to 80 potential respondents for the pilot study. A response rate of 37.5% enabled the analysis of 30 pilot study questionnaires. After further changes, 450 questionnaires were distributed through training and personnel managers from 10 major South African organisations sampling both the commercial and manufacturing business sectors. A response rate of 57% (240 questionnaires) allowed for the analysis of 234 usable questionnaires. The statistical analysis of responses was done by using both item and factor analytic techniques. After two phases of analysis a 20 item instrument with a three factor structure emerged. The first factor was labelled "anxiety behaviour in interpersonal situations", the second, "collaborative and complimentary behaviour", and the third factor "confronting behaviour". A sub-sample (n = 48) of peer-and self-ratings were correlated for each of the three factors to establish criterion-related validity. Results of this study supported the multidimensional and situation specific nature of the assertiveness construct. The value of developing measuring instruments suited to local conditions was also emphasised. However, the inadequate construct validity and reliability of the instrument indicates the need for further research before - application of the measure in decision making regarding the assertive behaviour of black employees
