The Role of Personality and Cognitive Ability in the Measurement of Usability

Investigating individual differences in human-product interactions can improve the development of usable products for a diverse range of users. This study explores personality and cognitive ability as predictors of usability. A sample of 972 respondents took the Mini-IPIP measure of Big Five personality, a matrix reasoning test for cognitive ability, and the System Usability Scale (SUS) as an assessment of usability across seven commonly used products (Microsoft Word, Google, Amazon, computer, Microsoft Excel, TV remote, microwave). We ran a hierarchical regression analysis, predicting SUS score from demographic variables (gender, age), then individual differences (personality, cognitive ability). The personality traits of emotional stability and openness were statistically and practically significant predictors of SUS across every product, and gender and conscientiousness were significant predictors across many products. Results suggest that the subjective assessment of usability is not impacted by cognitive ability, and that personality traits are small-to-moderate, but consistent, predictors of SUS score.