Grannies, tanning beds, tattoos and NASCAR: evaluation of search tasks with varying levels of cognitive complexity

One of the most challenging aspects of designing an interactive information retrieval (IIR) study is the development of search tasks. In this paper, we present preliminary results of a study designed to evaluate a set of search tasks that were developed for use in IIR studies. We created 20 search tasks using five levels of cognitive complexity and four domains, and conducted a laboratory evaluation of these tasks with 48 undergraduate subjects. We describe preliminary results from an analysis of data from 24 subjects for 10 search tasks. Initial results show that, in general, as cognitive complexity increased, subjects issued more queries, clicked on more search results, viewed more URLs and took more time to complete the task. Subjects' expected and experienced difficulty ratings of tasks generally increased as cognitive complexity increased with some exceptions. When subjects were asked to rank tasks according to difficulty and engagement, tasks with higher cognitive complexity were rated as more difficult than tasks with lower cognitive complexity, but not necessarily as more engaging. These preliminary results suggest that behaviors and ratings are fairly consistent with the differences one might expect among the search tasks and provide initial evidence of the usefulness of these tasks in IIR studies.