Abstract
Usability is now widely recognised as a critical factor to the success of e-learning systems. A highly usable e-learning system increases students' satisfaction and engagement, thereby enhancing learning performance. However, one challenge in e-learning is poor engagement arising from a "one-size-fits-all" approach that presents learning content and activities in the same way to all students. Each student has different characteristics and, therefore, the content should be sensitive to these differences. This study evaluated the students' perceived level of usability of an e-learning system that matches content to reading skill levels of students with dyslexia. 41 students rated their perceived usability of an e-learning system using the System Usability Scale (SUS). Results indicated that when the e-learning system matches content to students' skill level, students perceive greater usability than when the learning is not matched. There was also a moderate, positive correlation between perceived usability and learning gain when e-learning was matched to their skill level. Thus, students assessment of the usability of a system is affected by the degree to which it is suited to their needs. This may be reflected in increased engagement and is associated with higher learning gain.