Abstract
goes here. This is completion of the research and update of the previous work that was published in 2013[1]. The paper describes our recent experimental study of the impact of mobile screen size on the user comprehension of health information and application structures. An experiment was conducted to measure the impact of screen size on user comprehension and retention. Participants were given the same simple scenario, which consisted of searching from different menus, navigating and reading some contents. They were timed and tracked for correctness. Also, a follow-up survey was given to each participant that consisted of a rating scale to assess usability features, comprehension and retention abilities of the participants based on different mobile screen sizes. Results showed that there was a significant difference between mobile phone screen size and the time taken to read the contents, which was at its highest on small screens (p-value=0.02). Also, reading characters was hardest on a small screen (p-value=0.003). In addition, there was a significant difference between the three screen sizes regarding the organization of the application's information, showing that the smaller the screen size, the more organized the information. On the other hand, there was no significant impact of screen size on user comprehension, retention scores, number of errors or effective task completion but it was generally better if a large screen size was used. This study concludes that the screen size is not the main concern in comprehension of the contents or application structure. However, reading speed improves with the larger screen size and positively influences the task completion and understanding of the application elements.