The validation of the field-environment-duty occupational classification system and interest test

Abstract

Vocational interest is a dynamic, subjective, positive attraction towards a job, occupa tion or occupational field, based on the individual's perception of the structure of occupations and situations already experienced or expected to produce pleasurable feelings. Interest test tields are usually statistically derived from characteristics of individuals. This study develops and validates an interest test based on the perceived occupationaI structure. After examining various classification models and occupational classification systems, including work by Holland, Gati and Roe, a new network access model was pro­posed, based on many-to-many correspondence in set theory. Categories are arranged on levels. Choice of a category on one level precludes access to another category on the sanK level, but does not restrict access to categories on other levels. It was hypothesised that occupational structure is perceived to consist of the three levels of lields, environments and duties. Each category is a horizontal sirus group and includes all vertical status levels. Career choice is based on preferences at each level. 1200 jobs have been classified by allocation to one category on each level, and each is described by a field, environment and duty. The field-environment-duty (FED) system was operationalised in a ten minute interest test asking testees to choose from each level the three categories that interest them for a job. Extensive use was made of x to the power of 2 and empty sets to the power of two statistics in analysing nominal measurement scores. The FED test was applied to 1280 school-leavers in Gauteng, South Africa. Research supports Gati's division of occupations into "soft" (people-oriented occupations preferred by females), and "hard" (not-people-oriented occupations preferred by males), and introduces a third "neutral" division which is preferred equally by both males and females. Construct and concurrent validity was shown with the I 9Fll, VIQ, SDS and l6PF. In a four to five year longitudinal study the FED was found to predict future studies (80%) and occupation (86%). Research with working adults found that the FED test predicts concurrent job satisfaction, job tenure and self-assessed performance. Inter-rater reliability in assigning jobs to categories is around 80%. Test-retest reliability was significant to the 0,0001 level using the x to the power of 2 goodness of fit test.