The eye movements of 23 deaf subjects, ages 14 to 61 years, were recorded 30 times per second while the subjects watched four 2.5minute captioned television programs. The eye movement data were analyzed to determine the percentage of time each subject actually looked at the captions on the screen. It was found that subjects gazed at the captions 84% of the time, at the video picture 14% of the time, and off the video 2% of the time. Age, sex, and educational level appeared to have little influence on time spent viewing captions. When caption speed increased from the slowest speed (100 words per minute, or wpm) to the fastest speed (180 wpm), mean percentage of time spent gazing at captions increased only from 82% to 86%. A distinctive characteristic of the data was the considerable variation from subject to subject and also within subjects (from video to video) in regard to percentage of time spent gazing at captions.
The technology for captioning television programs for the benefit of people who are deaf or hard of hearing has been around since the early 1970s, and the first national closed-captioned television broadcast occurred on March 16, 1980. Since 1993, closed-captioned television decoders have been built into every television set with a screen larger than 13 inches. More and more captioning is being done, and in accordance with federal law, within a few years most programs will have closed captions.
Captioning is similar to subtitling and is the process of converting program audio to text and displaying that text on the screen. This is a much more complicated process than it may seem and requires many decisions concerning timing and screen placement. The captioning of television programming is a whole new profession, one that has grown very rapidly in recent years.
The eye movement of caption viewers is an important issue within the captioning industry because it influences many decisions on how captioning is done. Unfortunately, almost no research has been conducted to examine how people move their eyes when viewing captioned television.
The only recent research publication seems to be an article by Jensema, El Sharkawy, Danturthi, Burch, and Hsu (2000) that gave an overview of eye movement among captioned television viewers.
The present study takes that research by Jensema et al. (2000) a step further by examining the percentage of viewing time actually spent focusing on captions. We addressed four general research questions:
What percentage of viewing time do deaf people actually spend looking at captions?
Does the percentage vary with age, sex, and education?
Does the percentage vary from program to program and subject to subject?
Does caption speed influence the percentage of time spent viewing captions?
The present study utilized a modified version of the Eyegaze Development System designed by LC Technologies, Inc. This system, as modified by the Institute for Disabilities Research and Training, Inc. (IDRT), was described in detail by Jensema et al. (2000). Basically, the subject sits before a computer screen and watches a television program shown on the screen. A camera with an infrared light is mounted beneath the screen and the light is shined into one of the subject's eyes. The camera photographs the reflection of the light off the subject's eye and uses this information to calculate where the subject's eye is looking on the screen. These photographs and the calculations made from them are done 30 times a second. The coordinates on the screen where the subject is looking are entered in a computer file for later analysis.
Each subject is seated so that his or her eyes are between 18 and 22 inches from the computer screen. The video picture on the computer screen is 6 inches by 4.5 inches, a size that, when viewed from 22 inches away, is roughly comparable to an image viewed on a 27-inch television screen from 6 or 7 feet away. …