This article reports on the different methods of investigation employed to detect noncompliance with UI regulations, and their relative effectiveness. It considers a previous evaluation of the Unemployment Insurance Program for which a national random sample of UI claimants was selected from the active claimload and referred to Investigation and Control Officers for in-depth enhanced investigations. Results of these investigations, along with details of the specific control and investigation activities, were reported for analysis. A variety of investigation methods were generally combined, which meant that these were inter-correlated, making it difficult to apply standard regression analysis. Instead, principal components method is used for grouping of variables, and these are then entered into a logit regression model.