Organisation and memory

Abstract

Data from a series of experiments are reported in support of the context hypothesis developed in this thesis: recall and recognition are affected by the context in which items are perceived and the effects on recognition are most appropriately determined through reaction time (RT) measures as opposed to accuracy measures alone. Data are also reported which demonstrate instructional effects on recognition. The major independent variables manipulated were mode of presentation (simultaneous or serial), list structure (blocked or random) and practice (one trial or three trials) In addition, both a nested hierarchy and a categorized list paradigm were used as well as a paradigm involving the use of adjective modifiers. The data reported were consistent with the context hypothesis in that, generally, RTs were faster with a serial presentation and with a random list structure, and performance improved with practice. The effect of instructions was to attenuate recall and, especially, recognition effects. Two major approaches were compared with the context hypothesis and results discussed in those terms; the effective presentation time hypothesis and the dual-process approach. Neither was as effective in explaining the obtained results as the context hypothesis. The mechanisms involved in the context hypothesis were proposed as being an encoding specificity-variability process affecting encoding and an Atkinson/Juola search and decision process affecting retrieval. Nothing in the data contraindicated these processes. The context hypothesis is falsifiable, as was demonstrated in the final experiment reported, and is in a stage of development. This thesis reports the beginning phases of this development.