The purpose of the present study was to address some previously neglected but important issues with regard to research on the dimensionality of job characteristics. Variation in job characteristics across job categories was examined in this study, in contrast to previous research, which has focused investigation within jobs. On a sample of nearly 7,000 employees and 900 jobs, a three-factor solution was found to match best to an a priori structure using principal axis factor analysis, oblique factor rotations, and a procrustes transformation. This solution retained task identity and job feedback as legitimate job dimensions but detected a third dimension that collapsed skill variety, task significance, and autonomy into a single factor. Additionally, personal (age, education) and situational/contextual (position level) variables were found to influence the ability to differentiate among job characteristics. The results are discussed in the context of the findings of previous studies and future research needs.