Separable effects of factors on activation functions in discrete and continuous models: d′ and evoked potentials.

This article derives tests for partial-output models of information processing. A process in a partial-output model sends output, while executing, to its successors. In a stage model a process sends output to its successors only when it stops. Both models can be analyzed by manipulating factors, each affecting a different process. In discrete serial models, such factors have additive effects on reaction time (Sternberg, 1969) and sometimes on log percent correct (Schweickert, 1985). In partial-output models, such factors produce a simple pattern, the rectangle condition, in performance curves. Conditions for a partial-output representation are based on decomposable structures (Krantz et al., 1971). Tests of discrete and partial-output models are simultaneously satisfied only if performance is a linear function of time. Evoked potentials (Coles et al., 1985) and d' (Dosher, 1981) illustrate results.