ORIGINAL PAPER Evaluating the Problem Gambling Severity Index Thomas Holtgraves Published online: 14 August 2008 Ó Springer Science+Business Media, LLC 2008 Abstract A large, integrated survey data set provided by the Ontario Problem Gambling Centre was used to investigate psychometric properties of the Problem Gambling Severity Index (PGSI). This nine-item self-report instrument was designed to measure a single, problem gambling construct. Unlike its nearest competitor—the South Oaks Gambling Screen (SOGS)—the PGSI was designed specifically for use with a general population rather than in a clinical context. The present analyses demonstrated that the PGSI does assess a single, underlying, factor, but that this is complicated by different, multiple factor structures for respondents with differing levels of problem gambling severity. The PGSI also demonstrated small to moderate correlations with measures of gambling frequency and faulty cognitions. Overall, the PGSI presents a viable alternative to the SOGS for assessing degrees of problem gambling severity in a non-clinical context. Keywords Problem gambling Á Problem Gambling Severity Index Á South Oaks Gambling Screen Á Assessment of problem gambling Introduction The rapidly increasing availability of gambling in North America has made the assessment of problem gambling (and the potential for problem gambling) a clear research priority. Particularly important are brief, self-report instruments that can be used for research purposes (e.g., epidemiological studies) as well as serving as an initial problem gambling screen in clinical contexts. Numerous measures have been developed in this regard (see National Research Council 1999; Abbott and Volberg 2006; Stinchfield et al. 2007) but the most well-known and frequently used measure has been the South Oaks Gambling Screen (SOGS) (Lesieur and Blume 1987). The SOGS and related measures were developed primarily for use as problem gambling screens in clinical contexts. More recently, how- ever, alternative measures have been developed that were designed specifically for use with T. Holtgraves (&) Department of Psychological Science, Ball State University, Muncie, IN 47306, USA e-mail: 00t0holtgrav@bsu.edu 123 J Gambl Stud (2009) 25:105–120 DOI 10.1007/s10899-008-9107-7