Theory of Mental Tests
Theory of Mental Tests
The material in this book is based on my several years' experience in construction and evaluation of examinations, first as a member of the Board of Examinations of the University of Chicago, later as director of a war research project developing aptitude and achievement tests for the Bureau of Naval Personnel, and at present as research adviser for the Educational Testing Service. Collection and presentation of the material have been furthered for me by teaching courses in statistics and test theory at The University of Chicago and now at Princeton University.
During this time I have become aware of the necessity for a firm grounding in test theory for work in test development. When this book was begun the material on test theory was available in numerous articles scattered through the literature and in books written some time ago, and therefore not presenting recent developments. It seemed desirable to me to bring the technical developments in test theory of the last fifty years together in one readily available source.
Although this book is written primarily for those working in test development, it is interesting to note that the techniques presented here are applicable in many fields other than test construction. Many of the difficulties that have been encountered and solved in the testing field also confront workers in other areas, such as measurement of attitudes or opinions, appraisal of personality, and clinical diagnosis. For example, in each of these fields the error of measurement is large compared to the differences that the scientist is seeking; hence the methods of dealing with and reducing error of measurement developed in connection with testing are pertinent. Methods of adjusting results to take account of differences in group variability have been developed in testing, and they are helpful in arriving at appropriate conclusions whenever the apparent results of an experiment are affected by group variability. If measurements in any field are to merit confidence, the scientist must demonstrate that they are repeatable. Thus the theoretical and experimental work on reliability as developed for tests may be utilized in numerous other areas, as, for example, clinical diagnosis or personality appraisal. In any situation where a single decision or a . . .