Findings of a study that incorporated a method for measuring the economic efficiency of K-8 school districts in Illinois are presented in this paper. The quadriform concept was used to identify four categories, or quadrants, for identifying school districts--technically efficient, low service, high service, and technically inefficient. The method also utilized composite state standardized test scores rather than composite ACT scores. The main variables for classifying schools included composite 11th-grade reading and mathematics scores and district operating expenditures per pupil for the 1990-91 school year. A comparison of the quadriform formula with the former method indicates that the new technique resulted in changed school district classifications. Small, rural school districts were identified as technically efficient, and large central city and suburban districts were generally categorized as technically inefficient. A conclusion is that the quadriform concept is a useful tool for identifying technically efficient school districts. Seven figures are included. The appendix contains eight statistical tables (Contains 84 suggested readings.) (LMI)