Reliability, validity, and sensitivity of a single-item measure of online store usability

In an experimental study, we examined the validity and reliability of a single-item measure for customers' assessment of online store usability. Each of the 378 participants visited two out of 35 online stores and performed three shopping related tasks. Usability was rated using a single-item and an eight-item measure. In addition to trust in the online store and aesthetics, we also measured the participant's intention to buy. Results from factor analysis and the correction for attenuation formula revealed an adequate reliability of the single-item measure. Positive correlations with both trust and aesthetics supported the convergent validity of the single-item measure for usability. The positive correlation between the single-item and the intention to buy demonstrated the high predictive validity of this measure. Finally, results support the sensitivity of the single-item measure to differentiate between the usability for each online store.

Research Highlights
► We examined the quality of a new single-item measure for online store usability.
► Results revealed an adequate reliability and convergent validity of the measure.
► Moreover good predictive validity and sensitivity were demonstrated.
► We conclude that the single-item measure of usability is a useful instrument.