“…Dennis, personal communication, May 3, 2008), making it one of the most widely used measures in adolescent treatment. The GAIN’s main scales have been shown to demonstrate good internal consistency (alpha over .90 on main scales, .70 on subscales), test-retest reliability (Rho over .70 on days/problem counts, Kappa over .60 on categorical measures), and to be highly correlated with measures of use based on timeline follow-back methods, urine tests, collateral reports, treatment records, and blind psychiatric diagnosis (Rho of .70 or more, Kappa of .60 or more; Dennis, Chan, & Funk, 2006; Dennis, Ives, White, & Muck, 2008; Dennis et al, 2003). Copies of the instruments, manual, publications and documentation on the 100 plus scales in the GAIN are available at www.chestnut.org/li/gain.…”