Many books and numerous articles have been devoted to measurement approaches in sociobehavioral research (e.g., multiple-choice tests, rating scales, projective techniques, interviewing, observational methods) or even to specific aspects of a given approach (e.g., item characteristics, test equating, norms, response styles). Certain approaches have been developed and used primarily in the context of specific substantive areas (e.g., attitudes, achievement, mental abilities, personality, interests). Some approaches-generally referred to as measurement models-focus on differentiations among people, whereas others-generally referred to as scaling models-focus on differentiations among stimuli. Following is a small selection of books that address issues of measurement, scaling, or both: Coombs (1964), Coxon (1982), Edwards (I 957b ), Guilford (1954), Kruskal and Wish (1978), Maranell (l974b), McIver and Carmines (1981), Nunnally (1978), Torgerson (1958), and van der Yen (1980).