Objective: Lostness and disorientation are common consequences of information seeking in digital environments and can reduce search efficiency and decision-making quality. This study examines the effect of task complexity on lostness in browsing search and on disorientation in keyword search, while also testing the role of Posner’s attentional networks as a source of individual differences.
Method: The present study is a quasi-experimental study with a repeated-measures design in terms of its fundamental purpose and data collection method. The sample consisted of 96 graduate students from Shiraz University selected by simple random sampling. Attentional networks were assessed using the Attention Network Test (ANT). Participants performed four information-search tasks: simple and complex keyword-search tasks on Google, and simple and complex browsing-search tasks on Wikipedia. Navigation was recorded with ZD Recorder software; videos were reviewed and behavioral navigation indicators were extracted for each task. In keyword search, disorientation was calculated as a composite navigation index based on the standardized mean of multiple behavioral indicators. In browsing search, lostness was computed from the navigation graph using Smith’s index. Data were analyzed in two stages: (1) repeated-measures analyses to test the effect of task complexity separately for each search type, entering attentional networks as continuous covariates and testing complexity × network interactions; and (2) follow-up univariate analyses to examine network effects within each of the four conditions.
Findings: In browsing search, task complexity had a significant effect on lostness, with higher lostness in the simple task than in the complex task (p = 0.037), while complexity × attentional network interactions were not significant. In keyword search, task complexity had a highly significant effect on disorientation, with higher disorientation in the complex task than in the simple task (p < 0.001), while complexity × network interactions were not significant. Follow-up analyses indicated that executive control was significant in the simple conditions of both search types but not significant in the complex conditions.
Conclusion: Task complexity is significantly related to navigation indicators, but this pattern is not the same across the two search types. Attentional networks did not interact with task complexity. However, executive control appears more salient when users have greater opportunity for active engagement with the task (especially in simple tasks). These findings emphasize the need to interpret navigation indicators alongside outcome measures and to consider individual differences—particularly executive control—when designing search systems and training self-regulation strategies.