Abstract:

Computers and the Internet as sources of information retrieval and entertainment have become increasingly important. Web-based environments allow for combining different representational codes and addressing different sensory modalities which might be especially beneficial for users with special needs (eg. for blind people or for people with reading and writing disabilities). Our studies investigated which representational formats are beneficial to foster recognition and understanding of users with learning disabilities. As factors, we varied modality (visual, visual + auditory) and codality (text, text + pictures) aspects which led to a 2×2 design, whereas visual information was presented by means of symbols. Dependent variables were ratings of recognition and understanding in the first study and performance on recall in the second study. Participants were students from schools for special educational needs. Our results show that users profit mostly from auditorily presented information accompanied by symbols. This is in line with our expectations because research shows that only a few learners with learning disabilities are able to process written language in a meaningful way. The results are discussed with respect to their implications for ways to make web-based environments more accessible to disabled users.