Background - This study investigates subtitle usage as an essential element in video manuals for IT devices and apps and empirically analyzes the attention effects of the seniors and juniors according to the proximity of subtitles through eye tracking. This study also analyzes the differences in visual attention of seniors when compared to juniors. In this manner, the study proposes an effective production method regarding subtitle locations in educational videos and video manuals for the elderly.
Methods - The space where subtitles appear on the video screen was divided into short-, medium- and long- distance zones. About 20 seconds for each distance, a total of about 1 minute of experimental video, was shown. Through eye tracking, we investigated whether there was a difference in the total fixation count(TFC) and time to first fixation(TFF) by proximity.
Results - Both the senior and junior groups commonly showed that the farther the subtitle was from the app screen, the fewer the number of gazes, and the more varied the difference in the TFC became. Furthermore, there was a statistical difference in TFF between the short- and long-distance subtitles for both seniors and juniors. However, in both groups, there was no difference in the TFF between short- and medium-distance subtitles. These results suggest that the short- and medium-distances are spaces that can be used in selecting the positions of subtitles. There was a difference in the TFC for medium- and long-distance subtitles for seniors only.
Conclusions - In previous research, since subtitles should not interfere with video images in the news or documentary films, the most recognizable and effective subtitle location could be the bottom right. However, for the video manual, since the bottom-right position was the furthest distance from the image, it drew the least visual attention. In the short and medium distances, there was no difference in the attention of subtitles due to aging. Thus, it was a space that could be used when selecting the locations of subtitles. This study is significant because it investigates the visual attention of the elderly in comparison to juniors according to locations of subtitles. However, this study has limitations in that it examined visual attention through an eye tracker without revealing learning effects on learning videos. As a follow-up study, if not only visual attention but also recall is carried out, the effectiveness according to the location of subtitles is likely to increase.