“…Ogles et al (2000) also conducted additional analyses to investigate the extent to which the Ohio Scales were able to detect change over time. This was done by comparing one sample of case manager change scores on the Problem Severity and Functioning total scales to change scores on the Progress Evaluation Scales (PES; Ihilevich, Gleser, Gritter, Kroman, & Watson, 1981; higher values indicating both higher levels of functioning and lower levels of problems) twice over a four-month time period. The PES is a well-established outcome measure for detecting change over time.…”