ABSTRACT
This chapter describes several different mathematical formulations of information integration and evaluates the empirical support for each. It considers the psychological implications of each general type of formulation to be considered and attempt to identify the fundamental assumptions about information integration processes that underlie it. The chapter focuses on quite different assumptions about the processes involved than either a summative or an averaging model assumes. It explains to invalidate an averaging model that assumes that each piece of information presented has the same absolute weight. Aside from its ability to generate accurate quantitative predictions about the manner in which information combines to affect judgments, a model of information integration must be able to account for two well-established and apparently contradictory findings. Even if additive models can theoretically provide only approximate descriptions of information integration processes, they are still worthy of very serious consideration.
