Hands-free reading Braille with a vibrotactile wristband

In this paper, a new approach to display Braille is presented. Braille dots are mapped to six tactors of a vibrotactile wristband. The dot patterns of characters are displayed with adequate vibrotactile stimuli generated by the tactors. Compared to the conventional way of reading Braille, the advantage of the proposed approach is that there is no need to commit a hand to active Braille dot scanning and thus, the hand is still free for other activities or tasks. In a user study, different methods of mapping Braille to the wristband with respect to the assignment of cell dots to tactors as well as temporal aspects were evaluated using objective performance data and subjective ratings. Even with little training, promising results were obtained. Sequential mapping methods performed better than parallel methods and characters could be correctly recognized in up to 97% of cases

Ecological momentary assessment of digital literacy : Influence of fluid and crystallized intelligence, domain-specific knowledge, and computer usage

The ability to comprehend new information is closely related to the successful acquisition of new knowledge. With the ubiquitous availability of the Internet, the procurement of information online constitutes a key aspect in education, work, and our leisure time. In order to investigate individual differences in digital literacy, test takers were presented with health-related comprehension problems with task-specific time restrictions. Instead of reading a given text, they were instructed to search the Internet for the information required to answer the questions. We investigated the relationship between this newly developed test and fluid and crystallized intelligence, while controlling for computer usage, in two studies with adults (n1 = 120) and vocational high school students (n2 = 171). Structural equation modeling was used to investigate the amount of unique variance explained by each predictor. In both studies, about 85% of the variance in the digital literacy factor could be explained by reasoning and knowledge while computer usage did not add to the variance explained. In Study 2, prior health-related knowledge was included as a predictor instead of general knowledge. While the influence of fluid intelligence remained significant, prior knowledge strongly influenced digital literacy (ß=.81). Together both predictor variables explained digital literacy exhaustively. These findings are in line with the view that knowledge is a major determinant of higher-level cognition. Further implications about the influence of the restrictiveness of the testing environment are discussed