This publication describes some of the work of the UNESCO Division of Statistics on Education on the evaluation of the internal efficiency of educational systems that followed from the 1970 International Conference on Education. The first section contains a brief summary of the conclusions of the "Expert Meeting on the Evaluation of Internal Efficiency of Educational Systems" held by UNESCO in January 1972. The second section contains a paper by Z. Hellwig entitled "Wastage Prediction Method," which was prepared for discussion at the Expert Meeting. The third section contains some technical notes by D. Blot on Professor Hellwig's paper. The fourth section contains a paper by A. Brimer entitled "The Quantification of School Events Related to Educational Wastage," which was also prepared for discussion at the Expert Meeting. (JG)