Investigating The usability of iconography via brain and key-press responses

The purpose of this research is to better understand the circumstances in which icons are most effective in use cases that pertain to memory. To achieve this, the project aimed to investigate the research question: "How do the pre-existing icon classifications discussed by Arledge and Nielsen impact memory performance?". The classifications in use are Solid and Outline & Resemblance and Abstract icons. Current research on the usability of these classifications suggests there is no clear superior classification in either family regarding the speed or accuracy in which they are identified. Despite this, current research regarding both the N-Back task and electroencephalogram (EEG) indicates that these tools remain effective in providing quantitative insights on memory load and the timing of memory recall. Twelve students at the University of Kent participated in an experiment where each participant conducted separate 1-back and 2-back tests (variants of the N-Back test) for each of the four permutations for both families of classifications (Solid Resemblance, Solid Abstract, Outline Resemblance, Outline Abstract). Eight tests were conducted by each participant. During each test, the reaction times of participants (in milliseconds) and the participant's EEG data was recorded in parallel. A 32-channel wireless brain-computer interface (BCI) was used to collect the EEG recordings. The statistical analysis conducted on the data provided by the N-Back tasks and ERPs employed the Wilcoxon signed rank test to test for significant differences between the stimuli classifications used. The comparisons made on the N-Back reaction times show that Arledge's two icon styles Solid and Outline failed to outperform each other significantly in terms of the speed at which they were recalled. Contrary to previous work favouring resemblance icons due to their suggested superior usability over abstract icons, comparisons showed that abstract icons were recalled significantly faster than resemblance icons, this observation was made when the two semantic groups were in an outline style. Dually, a comparison made showed an instance in which abstract icons in an outline style elicited a significantly smaller amplitude compared to resemblance icons in the same style, indicating an increased memory load compared to resemblance icons. User interface design principles of previous work, would suggest that Outline Resemblance stimuli had better usability than Outline Abstract stimuli, due to a significantly lower memory load. Despite these observations, overall, the ERP analysis did not reveal any significant distinction between the memory loads of the icon classifications used. To observe significant differences between the icon classifications used, this study suggests that future work explores the impact of various dimensions on memory performance.