The purpose of this research was: (1) to assess the performance of the CPGI in meeting its objectives and (2) to inform the periodic refinement of the CPGI. The primary research design was a key informant survey, using a semi structured format, examining the experiences of the Original Developers of the CPGI and the Principal Investigators that have conducted CPGI prevalence studies in Canada and other jurisdictions. Almost all respondents consider the CPGI to have met its original objectives "well" and a few "very well". Most consider the CPGI to be an improvement over previous instruments. Overall, the PGSI is considered successful in measuring gambling broadly by including behaviours and adverse consequences and introducing defined categories for non-problem gamblers, low risk gamblers, moderate risk gamblers and problem gamblers. In addition, this categorization schema is viewed as aiding prevention efforts. A large majority of the respondents think the CPGI has been successful in describing a new, more meaningful, broader, holistic, theory-based measure of gambling and problem gambling in the general population. About two thirds of the respondents consider the CPGI to have been successful in measuring prevalence of gambling and problem gambling in the general population. The supporters note that the CPGI identifies the large group of "low risk" and "moderate risk" gamblers who were not identified by other survey instruments. The CPGI is considered to have provided a consistent measure of gambling and problem gambling across Canada. About half of the respondents consider the CPGI to have been successful in including adequate indicators of the environment and social context. The positive respondents consider the CPGI to do a better job than other instruments, recognizing that other instruments did not try to include indicators of the environment and social context. A large portion of the respondents indicated that the CPGI performs well in describing Gambling Involvement, with some considering this area to be comprehensive and thorough. In general, respondents consider the PGSI to do a very good job of measuring problem gambling. In contrast to other instruments, respondents particularly appreciate the multiple response choices in the PGSI (instead of just yes or no answers). A few suggest we cannot accurately measure problem gambling until we understand more about its nature. It was pointed out that the CPGI recently won a comparative review in Australia against the Victorian Gambling Screen and the South Oaks Gambling Screen.