Usability tests for personalised subtitles

Over the past decade, subtitles have developed along with broadcast and broadband technology. Viewers nowadays enjoy new opportunities to customize subtitles to best meet their personal preferences or needs. This study aims to identify end-user subtitle setting preferences, to investigate whether these settings have an effect on content comprehension, and to explore subtitle usability for two groups of participants, those under the age of 65 and those over 65. In an experiment, three subtitle features were open to customization: the position, the box and the size of the subtitle, before and after participants watched an on-demand TV documentary produced by the Catalan public broadcaster TVC. Results confirm a preference for bottom and medium subtitles. Furthermore, while the under 65 segment made satisfactory use of the system, the over 65 segment experienced different levels of usability and reported different capabilities and problems.