Effects of Work Group Size and Task Size on Observers' Job Characteristics Ratings

The effects of number of workers (work-group size) and number of tasks (task size) on perceptions of job enrichment were investigated using a simulated assembly-line job. Forty subjects observed workers performing a job in four combinations of work-group size and task size, rating the respective jobs on dimensions taken from the Job Characteristics Model (Hackman & Oldham, 1975). The results indicated that jobs performed by smaller work groups were perceived as significantly more enriched on four of the five dimensions and had greater potential for worker motivation. Significant main effects were also found for task size on three of the five dimensions such that jobs with larger tasks were seen as more enriched and as having greater motivating potential for the workers. A significant interaction was noted for only one job dimension. An ecological perspective of the data (manning theory) supported these results and suggests theoretically useful interpretations of the data.