The composite indicator, published annually by the Educational Research Service (ERS), was designed to reflect overall changes in average salaries and wages paid by public school systems. The purpose of this book is to describe the nature of the indicator, how it is compiled on a national and state basis, and how local school systems can compile data for use in salary and wage decision-making. The composite indicator is based upon data for 28 of the 33 public school employee positions on which ERS reports. For example it shows that changes in average salaries and wages paid by reporting school systems in 1978-79 increased by 6.7 percent over those paid in 1977-78. This compares with a 7.7 percent increase in the Consumer Price Index for calendar year 1978. Procedures, work sheets, and outline graphs for making local computations and comparisons are included in the final section of this information aid. (Author/LD)