 They claim that the subscales produce easily interpretable data which describe the extent to which substitutes for leadership are present or absent in a given work situation.They went on to test their subscales in a field setting using police officers, and concluded that the subscales met acceptable standards of reliability, and can be used to assess the validity of the substitutes for leadership construct in future studies.Podsakoff, Niehoff, MacKenzie, and Williams (1993) noted that studies testing the substitutes for leadership model had not been fully supportive of the theory, and believed that one reason for this may be that the quality of the scale developed by Kerr and Jermier (1978) to measure the substitutes constructs may be to blame.