This report is a critical evaluation based on extended field trials and theoretical analysis of the time-span technique of measuring level of work in organizational hierarchies. It is broadly concluded that the technique does possess many of the desirable features claimed by its originator, but that earlier, less highly structured versions based on detailed job content analyses show more promise than the later "shortened" version, which appears to yield rsults of questionable reliability. The critique is illustrated by field case study material wherever possible. (Author)