This study was a follow-up to determine the psychometric quality of the usability questionnaire items derived from a previous study (Ryu and Smith-Jackson, 2005), and to find a subset of items that represents a higher measure of reliability and validity. To evaluate the items, the questionnaire was administered to a representative sample involving approximately 300 participants. The findings revealed a six-factor structure, including (1) Ease of learning and use, (2) Assistance with operation and problem solving, (3) Emotional aspect and multimedia capabilities, (4) Commands and minimal memory load, (5) Efficiency and control, and (6) Typical tasks for mobile phones. The appropriate 72 items constituted the Mobile Phone Usability Questionnaire (MPUQ), which evaluates the usability of mobile phones for the purpose of making decisions among competing variations in the end-user market, determining alternatives of prototypes during the development process, and evolving versions during an iterative design process.
Practitioner’s Take Away
- The MPUQ can have a substantial and positive effect on evaluating the usability of mobile products for the purpose of making decisions among competing product variations in the end-user market, alternative prototypes during the development process, and evolving versions of a same product during an iterative design process.
- Usability researchers, practitioners, and mobile device developers will be able to take advantage of MPUQ or the subscales of MPUQ to expedite their decision making in the comparative evaluation of their mobile products or prototypes.
- The MPUQ is particularly helpful in evaluating mobile phones, because it is the first usability questionnaire tailored to these products.
- The questionnaire can serve as a tool for finding diagnostic information to improve specific usability dimensions and related interface elements.