Think-aloud usability testing of an app to increase physical activity

Abstract

Background Insufficient physical activity is one of the most important risk factors for non-communicable diseases and should therefore be intensively prevented in all age groups. According to several trials, activity can be effectively increased by smartphone-based interventions. However, the use of digital applications depends on many factors such as user acceptance and intuitive operability. Therefore, usability testing has proven to be important for the successful development of digital interventions. Thus, the German app “VIDEA bewegt” was tested on its usability in order to assess the strengths and weaknesses of the product and to improve of the app.Methods In April 2019 ten interviews were conducted using the think-aloud method and following a standardised protocol. The adult participants were confronted with “VIDEA bewegt” for the first time and had to perform pre-defined tasks covering the main features of the app. Demographics of the participants and their expectations towards an app were collected. The interviews were recorded and transcribed. The analysis of the transcripts was performed independently by two team members following the deductive qualitative content analysis according to Mayring.Results The app was rated positively in terms of design, basic registration process and the largely self-explanatory navigation. Users found the app lacked an explanation of the included components and the basic structure of the programme. Several problems with the usability were described, including technical errors and problems with understanding individual control elements. Four of the ten participants could imagine using the app in the future.Conclusions All test participants were able to use the app independently to a large extent and most of the a priori defined goals were achieved successfully. With certain minor changes, the usability can therefore be assessed as good.Trial registration The performed usability test is the basis of a study named “Evaluation of an app-based activity intervention for statutory health insured people” which is registered in the German Clinical Trials Register (DRKS). DRKS-ID: DRKS00017392 (14 June 2019)