A scale was constructed to test Hershenson's 1968 formulation that in vocational development, self-differentiation precedes competence, which precedes independence, which in turn precedes commitment. Staff ratings on scale items related to each stage were made on 222 clients in a deaf rehabilitation project, who were divided into high- and low-functioning (socially and vocationally) workshop and counseling groups. Support for the posited sequence of purely intrapsychic stages of vocational development was found. (Author)