Hypertext refers to a collection of documents containing links that allow readers to move from one chunk of text to another. Hypertext may increase cognitive load relative to the processing of regular text. Cognitive load consists of mental load, mental effort and performance. Working memory refers to the set of mental resources that people use to encode, activate, store and manipulate information while they perform cognitive tasks. Increased mental load is associated with reduced performance in hypertext reading. Executive functions include decision making, coordination of task demands and inhibition of irrelevant information. Situation models refer to complex mental representations formed when readers integrate the statements in the text with their knowledge. The interruption of going from one hyperlink to another may have minimal effects on comprehension if the next text is related to and enhances the developing situation model. It is possible that interruptions in reading impair situation model formation. Learning tends to be better when there are fewer links in a hypertext. Increasing the number of links may increase cognitive load and impair learning. Networked hypertexts may impair a reader’s efficiency navigation. In general, the more links, the slower the navigation will be. It seems that people perform best when there are a lot of choices in the introductory screen and fewer choices at deeper levels of the hierarchy. A hierarchical structure of a test generally helps navigation. Readers with low working memory spans benefit from structured texts and from organizers that highlight text structure. Hypertexts may be less appropriate for low working memory span readers. Individuals who are poor at keeping verbal representations active in memory may be disadvantaged because related sentences may be spread further apart in non-hierarchical hypertexts. The flexibility of hypertext may be beneficial for readers who are positioned to...