The role of situational information in conceptual knowledge
This thesis investigated the influence of situational knowledge on the performance of two common tasks; category member generation under a free-emission procedure and the judgement of similarity between two items using rating scales. In both tasks, self-report protocols were used to identify the strategies that people seemed to be using to complete the tasks. The main goal was to identify the role of situational knowledge in the organisation of semantic memory. Traditional models would not predict a role for situational knowledge in either of the target tasks. In the category member generation studies (Chapter 2) participants frequently instantiated situations or perspectives to cue retrieval of category members for both taxonomic and ad hoc categories. Chapter 3 investigated the factors that determine subjective similarity: category type, typicality, context and presence or absence of self-report. The quantitative data analysis showed the need for careful qualifications to previous claims concerning the effect of context on similarity (Barsalou, 1982). Specifically, ad hoc category members were rated more similar with context only when judgements were made without self-report and when items were relatively typical. Self-report protocols showed that co-occurrence of items in a situation frequently entered into judgements of similarity. Chapter 4 investigated the role of events in determining the strength of this 'thematic' similarity. Individual indices of association strength between the items and an event were shown to predict similarity ratings - thus confirming that thematic similarity is driven, at least partially, by the association of items to common settings. The findings lend empirical weight to theoretical positions that present memory for situational information as an integral part of conceptual knowledge. This approach may underpin a new direction for research into concepts in both normal and clinical adult populations.