['The purpose of this paper is to determine the effectiveness of web-based video lectures on demand for the deaf in comparison to the traditional method of teaching using a sign language interpreter. The web-based lectures presented are specifically designed for the deaf in education and in rehabilitation.', "Sixty-three deaf students and adults were divided into four groups. All of the groups were made up of users who shared similar knowledge in the field of computers, but with different abilities in using computers, from beginners to advanced users. All of the groups were of mixed gender. The first two groups (consisting of 23 test users) graded the usability of the user interface for web-based lecture on demand with the help of the standardized SUMI questionnaire. After that, two groups (20 students from high school and 20 adults) joined in a 45-min informational program on the history of the deaf. Both groups were then divided into two smaller subgroups of 10 participants. The first subgroup in the first part of the learning program followed a traditional teaching style with the help of a teacher and an interpreter for Slovenian sign language. Meanwhile, the second group observed a 12-min web-based video lecture on demand and still had available an additional 18 min for a more detailed observation of the video. At the end of the lecture, the teacher used the questionnaire to review the participants' understanding of the content of the lecture in both of the groups. During the entire testing period, the interpreter used Slovenian sign language.", 'By using the SUMI questionnaire, we determined the usability of the user interface for comprehension and gathering of knowledge. We discovered that the system was usable according to the standards. The global Median results (Global Median=51) were in the range of 50. In the second part of testing, we determined the level of significance between the traditional and web-based lectures. The results were statistically evaluated using the t-tests and the ANOVA test. From the t-tests we established the hypothesis that the number of correct answers for both groups (group 1: web-based, group 2: traditional) differed. The t-test used for the age groups rejected the hypothesis that the number of correct answers for both groups differed, where group 1 was comprised of adults and group 2 was comprised of students. Additionally, the ANOVA test showed that the number of correct answers for adults using traditional lectures differed significantly from the number of correct answers for both adult and student web-based users. The ANOVA test showed no differences between any of the remaining groups.'] Does the role of video technology in on-line lecture for the deaf?