James R Lewis1. 1. 525817 IBM Corp., Delray Beach, Florida, USA.
Abstract
OBJECTIVE: To assess versions of the shorter form variant of Usability Metric for User Experience (UMUX-LITE) questionnaire differing in the number of response options for the items (3, 5, 7, and 11). BACKGROUND: The UMUX-LITE is an efficient (two-item) standardized questionnaire that measures perceived usability. A growing body of evidence shows it closely corresponds to one of the most widely used standardized usability questionnaires, the System Usability Scale (SUS), with regard to both correlation and magnitude of concurrently collected means. Although the "standard" version of the UMUX-LITE uses items with seven response options, there is some variance in practice. METHOD: Members of a corporate user experience panel (n = 242) completed surveys rating a recent Web site experience with the SUS and UMUX-LITE, also providing ratings of overall experience and likelihood-to-recommend. RESULTS: Scale reliabilities were acceptable (coefficient α >.70) with the exception of UMUX-LITE with three response options. All UMUX-LITE correlations with SUS, overall experience, and likelihood-to-recommend were highly significant. For likelihood-to-recommend, there was a significant difference in the magnitude of correlations, with 11 response options higher than three. Although some statistically significant differences were observed in correspondence between SUS and UMUX-LITE scores, these did not seem to translate to practically significant differences. CONCLUSION: The number of UMUX-LITE response options does not matter much, especially in practice. Because the version with three response options showed some weakness with regard to reliability and correlation with likelihood-to-recommend, practitioners should avoid it. APPLICATION: Unless there is a strong reason to do otherwise, use the "standard" version with seven response options.
OBJECTIVE: To assess versions of the shorter form variant of Usability Metric for User Experience (UMUX-LITE) questionnaire differing in the number of response options for the items (3, 5, 7, and 11). BACKGROUND: The UMUX-LITE is an efficient (two-item) standardized questionnaire that measures perceived usability. A growing body of evidence shows it closely corresponds to one of the most widely used standardized usability questionnaires, the System Usability Scale (SUS), with regard to both correlation and magnitude of concurrently collected means. Although the "standard" version of the UMUX-LITE uses items with seven response options, there is some variance in practice. METHOD: Members of a corporate user experience panel (n = 242) completed surveys rating a recent Web site experience with the SUS and UMUX-LITE, also providing ratings of overall experience and likelihood-to-recommend. RESULTS: Scale reliabilities were acceptable (coefficient α >.70) with the exception of UMUX-LITE with three response options. All UMUX-LITE correlations with SUS, overall experience, and likelihood-to-recommend were highly significant. For likelihood-to-recommend, there was a significant difference in the magnitude of correlations, with 11 response options higher than three. Although some statistically significant differences were observed in correspondence between SUS and UMUX-LITE scores, these did not seem to translate to practically significant differences. CONCLUSION: The number of UMUX-LITE response options does not matter much, especially in practice. Because the version with three response options showed some weakness with regard to reliability and correlation with likelihood-to-recommend, practitioners should avoid it. APPLICATION: Unless there is a strong reason to do otherwise, use the "standard" version with seven response options.