Reduction of Cognitive Workload through Information Chunking

Two experiments were conducted to determine whether grouping of icons on complex graphic displays reduces information processing loads, as measured by the Subjective Workload Assessment Technique and errror rates. In Experiment 1, between 2 and 25 symbols were presented on a computer display. Participants were asked to chunk symbols under class labels and store these labels in short-term memory. Two different display formatting variables were tested: spatial proximity grouping of icons was manipulated across three levels, while temporal grouping was manipulated across two levels. Results suggest that display grouping helps operators organize, encode, and store information into task relevant chunks and, in turn, reduces subjective workload and error rates. Experiment 2 was similar to Experiment 1, except that participants were required to remember individual icon names (i.e., participants were asked to remember as many as 25 item names). Results suggest that for chunk formation, storage, and parsing tasks, display grouping may reduce subjective workload, but not error rates.