The goal of this research is to design a tool to assess intuitiveness of products. Existing scales such as INTUI (Diefenbach and Ullrich 2015) show some limitations when used by children and/or for evaluating non-digital products. We aim to obtain a more universal questionnaire tool. INTUI questionnaire measures the components of an intuitive interaction (Effortlessness, Gut feeling, Magical experience, Verbalizability and Intuitiveness) through 17 items. After removing or rephrasing several items, we tested a revised version (8 items) with 68 participants (children and adults) who performed a task (a drawing for children and subtractions for adults) with a digital device (tactile tablet for children and smartphone for adults) and a non-digital device (paper and pencil). The results led us to remove the "Verbalizability" and "Gut feeling" dimensions which were difficult to understand and inconsistent with the conceptual model. The final version of the questionnaire (5 items) including three dimensions (Effortlessness, Magical Experience and Intuitiveness) was tested with 69 adults to evaluate a Coffee Dispenser Machine. Both "Effortlessness" and "Magical experience" dimensions seem to reliably predict intuitiveness.
Relevance to human factors / ergonomics theoryNowadays, users and industry want to have intuitive products (Fischer et al. 2009;Grandhi et al. 2011;Lagerstam et al. 2012;Naumann et al. 2008). Intuitivity is a prerequisite for users and a sales pitch for companies. Intuitiveness is not only a key dimension of usability (ISO 9241-210) but also of universal design (Story et al. 1998; third principle), that generalizes usability to all groups of users. Different methods allow to evaluate the intuitiveness of a product. In our work, we used the INTUI questionnaire, however, we found that it was not understood by all categories of users, especially children, and that it did not allow us to evaluate any type of product, especially those that are not digital. Our goal is to offer a simplified version usable with the largest number of users and products.To our knowledge, the group named "Intuitive Interaction Research" is the main research team that has studied this concept. Blackler, Popovic, and Desai (2018) reviewed the research method toolkit to measure intuitive interaction. Data collection methods include observation, verbal protocol, interview, diary, application of schemas and questionnaires. Among these tools, the INTUI questionnaire (Diefenbach and Ullrich, 2015) aims to understand