European Portuguese Validation of Usefulness, Satisfaction and Ease of Use Questionnaire (USE)

Background: The Usefulness, Satisfaction and Ease of use (USE) is a 30-item questionnaire developed to assess self-perceived usability. Objective: The study reported in this paper supports the translation, cultural adaptation and validation of the European Portuguese version of the USE. Methods: The study was divided into two phases, the questionnaire translation and adaptation, and the assessment of its validity and reliability. Results: The questionnaire translation resulted in a European Portuguese version of the USE equivalent to the original version in terms of semantic and content, which presents an excellent internal consistency (alpha = 0.80), highly satisfactory ICC values (ICC = 0.69) and a high and significant correlation (r = -0.84, p < 0.05) with another widely used usability questionnaire, the Post-Study System Usability Questionnaire. Conclusion: The European Portuguese version of the USE has adequate psychometric properties that provide adequate evidence of the possibility of using this version in studies to evaluate the self-perceived usability of products or services.