Design and evaluation in the large of health apps for the general population with case studies in mindfulness, neurological and psychological assessment

Nowadays, there is a high number of health apps, i.e. apps aimed at helping people learn, track and improve health conditions and behaviors, available on on-line app stores, such as Apple’s App Store and Google Play, as well as on social networks, such as Facebook. However, very few of these apps have been created by healthcare experts or have been scientifically evaluated, posing the risk that they might be ineffective or even detrimental to people. In this thesis, we have explored how HCI design and evaluation methods can be applied for proposing effective health apps that target the general population. In particular, we focused on three domains, i.e. (i) mindfulness, (ii) psychological assessment, and (iii) neurological assessment, and proposed an app for each domain. Then, to improve their design or assess their efficacy in different contexts of use, we carried out quantitative and qualitative short- and long-term studies. To this purpose, we employed traditional HCI user-centered design methods, i.e. lab and in situ studies, as well as a recently proposed method, i.e. research in the large, to possibly recruit a large number of users. In the thesis, for each proposed health app, we discuss the results of the evaluations we carried out, as well as pointing out strengths and limitations of the particular study methodology employed. Finally, we outline possible future work