Shakers and Maracas: Action-based Categorisation Choices in Triads Are Influenced by Task Instructions

The forced-choice triad task has become increasingly popular in use over recent years. While it is seen as being a categorisation task (Lin & Murphy, 2001) variation in task instructions often leads to different results. Shipp, Vallée-Tourangeau, and Anthony (2014) used the triad task to show that when participants are asked to choose an option that ‘goes best with the target’, they are more likely to select the choice that shares an action relation when it also shares taxonomic information. However using the instruction to select the item that “goes best” is vague and might encourage a strategy other than a categorical decision. The present experiment used the same triads as in Shipp et al. to test whether participants would match items based on shared actions or shared taxonomic relations when given specific categorisation instructions. The task instructions were manipulated so that participants either selected the item that “goes best”, “goes best to form a category” or is “most similar” to the target. The results found instances where the instructions of “goes best to form a category” led to a higher probability that participants would select the action choices over the instructions of “goes best”. However when participants were encouraged to use similarity overall action choices were lower. Therefore the triad task does encourage a natural categorisation strategy and differences in task instructions across research are a result of the stimuli used.