Risk Ranges explained:  Risk & Needs tests determine client risk by a series of equations, which classify clients according to four risk ranges. These risk ranges and the percentages of clients expected to fall in each risk range are as follows: low (zero-39^th percentile or 39%), medium (40-69^th percentile or 30%), problem (70-89^th percentile or 20%) and severe problem (90-100^th percentile or 11%). A problem is identified when a client’s scale score is at or above the 70^th percentile. These percentages were initially derived from available literature. Subsequently they have been empirically upheld and endorsed by our peers and test users across the United States.

Validity analyses support the use of these risk ranges. Problem risk (70^th percentile and above) identifies at least 98 percent of clients who have problems. In these analyses, clients who have had treatment are assumed to have problems. These clients are compared to clients who have not had treatment (no problem). Within these two groups, clients who scored at or above the 70^th percentile are compared to clients who scored at or below the 39^th percentile (low risk). In every analyses studied, at least 98 percent of the clients who had treatment scored at or above the 70^th percentile. These findings support the 70^th percentile as the threshold for identifying problems.

These analyses include alcohol (treatment versus non-treatment), drugs (treatment versus non-treatment), violence (arrests versus non-arrests) and other problematic behaviors.  In all of these studies at least 98 percent (in some 100%) of the problematic offenders/clients were identified.  These analyses are discussed in both Annual Summary Reports and Test Summary Reports presented on the Annual Summary Reports webpage.

Risk range percentiles are established so that scale scores can be interpreted and applied to establishing levels of supervision and treatment options when applicable. Percentiles give meaning to scale scores. They answer the question "What does this scale score mean?" This also allows comparison with other scores. Percentile scores range from zero to 100. They tell you the percentage of clients that scored lower. For example, if a client has a percentile score of 90, this means that 90 percent of all clients’ tested scored lower than that score. Applying this to level of risk, a percentile score of 90 means that 90 percent of all clients tested had less risk. In other words, the 90 percentile client is a high risk.