Issues in using quantitative rating scales in developmental research.

Abstract

Theoretical and practical issues in the use of quantitative judgments in developmental research are reviewed. Judgment is conceptualized as consisting of three components: information valuation, information integration, and translation of impressions into overt responses. It is important to distinguish between developmental changes that occur in different components of the judgment process. Most developmental studies have assumed that rating scales are used in an equal-interval manner, with few attempts to test that assumption. The conditions allowing a conclusion that individuals or groups differ in information integration are outlined, and methods of testing models of the information integration process that do not assume an equalinterval response scale are reviewed. Although these methods require more complicated experimental designs, their benefits in identifying the possible loci of developmental changes in judgments outweigh their inconvenience. Development can be characterized as involving change in the organization and modes of using information. Modem developmental psychologists study many tasks that require the individual to use multiple sources of information to make various types of judgments. Interest in the way information from multiple sources is used appears to be based on the belief that these processes can reflect fundamental aspects of cognition. For example, Piaget (1965; Inhelder & Piaget, 1958) proposed that there are developmental shifts both in the amount of information children use and in the way the information is used. Piaget's theoretical proposals about developmental change were based largely on patterns of behavior observed in multiattribut e tasks (e.g., conservation, perspective taking, moral judgment, and problem solving). An important current approach to development in such tasks is to collect quantitative judgments and use them to test mathematical representations of the cognitive processes of combining information. The growth in pop