Preface The basic purpose of a personnel selection program is to choose those applicants who are most likely to complete their training and become successful performers on the job. The successful matching of candidates to job requirements is in the best interests of the individual and the organization. Although mismatching is expensive in terms of wasted training effort@ accidents@ and operating errors@ most organizations adjust and survive-some don't. Mismatching has more serious consequences for the individual in terms of misdirected energy@ frustration@ disillusionment@ injury@ and even death. At the very least@ the individual wastes part of a life. These are reasons enough to require a sound selection program. When selection procedures have an adverse impact on certain groups protected by law@ it is also necessary to demonstrate the validity of those procedures in accordance with the Uniform Guidelines on Employee Selection Procedures@ 1 published by the federal agencies in 1978. While these guidelines were in the draft stage@ the Subcommittee on Personnel Selection prepared written comments and also testified at a public hearing in Washington@ D.C. This effort was aimed at making the guidelines conform as closely as possible to sound professional practice. While some improvement resulted@ the published guidelines are complex and very detailed. Their effect has been to discourage employers from using sound selection procedures and to encourage the hiring of minimally qualified applicants in order to meet set goals. During the year or more that the Uniform Guidelines were under public review@ the subcommittee had already begun a research project aimed at determining whether certain selection tests were generally valid throughout the petroleum and petrochemical industry. We hoped to find tests that could be transported from one location to another@ and from one company to another@ without revalidating the tests. In this project we pooled a large number of studies from 14 different companies. This massive data base was analyzed using a new mathematical model developed by Drs. Frank Schmidt and John Hunter. This monograph gives details on two selection tests proven to be valid in selecting candidates for a wide variety of operations and maintenance jobs. The project is continuing@ and we hope to evaluate further selection instruments for validity generalization. The Subcommittee on Personnel Selection wishes to thank the companies that participated@ Dr. Frank Schmidt who was the principal investigator on this project@ Drs. R. Stephen Wunder and James W. Herring who prepared this monograph@ and Elizabeth S. Sechler who coordinated and developed the data base. 1. Federal Register@ Uniform Guidelines on Employee Selection Procedures. 1978@ Vol.43.No.166@ Part IV@ Washington@ D.C.: Government Printing Office@ August 25@ 1978.pp.38290-38315.