Assessing Cognitive Load on Web Search Tasks

TL;DR

This study investigates how cognitive load during web search tasks affects user performance and highlights the complexities in measuring mental effort through dual-task methods.

Contribution

It provides empirical evidence on the relationship between task difficulty, cognitive load, and secondary task performance in web search scenarios.

Findings

Primary task performance correlates with task difficulty.

Objective and subjective difficulty relate to primary task performance.

Dual-task measures may not reliably indicate cognitive load.

Abstract

Assessing cognitive load on web search is useful for characterizing search system features and search tasks with respect to their demands on the searcher's mental effort. It is also helpful for examining how individual differences among searchers (e.g. cognitive abilities) affect the search process. We examined cognitive load from the perspective of primary and secondary task performance. A controlled web search study was conducted with 48 participants. The primary task performance components were found to be significantly related to both the objective and the subjective task difficulty. However, the relationship between objective and subjective task difficulty and the secondary task performance measures was weaker than expected. The results indicate that the dual-task approach needs to be used with caution.