The Illinois project entitled Measurement and Evaluation of Public Library Services is being conducted by the Library Research Center (LRC) at the University of Illinois. The long range goal of the project is to make available meaningful information for the evaluation and improvement of local public libraries. Two immediate objectives are to test the Public Library Association (PLA) performance measures manual in a representative sample of Illinois public libraries of various sizes and to teach a sample of library personnel the data collection techniques necessary for applying the PLA performance measures. Since operating expenditures proved to be the significant variable related to library size, public libraries were stratified by operating budget for the four areas of the state, and a random sample drawn. The LRC staff held six workshops to teach the PLA procedures to staff from the library systems and from the selected public libraries. Trainees were then asked to conduct a three-day performance measures study in their own library, tabulate their data, and send the results to the LRC, along with comments on the manual. When all of the data is received, the LRC will create individual library profiles and establish performance levels for libraries of each budget level. (Author/SL)