The Effects of Graphical Overviews, Prior Knowledge, and Self-Concept on Hypertext Disorientation and Learning Achievement

JI. of Educational Multimedia and Hypermedia (2003) 12(2), 117-134 To counter user disorientation and cognitive overload, hypertext environments often incorporate navigational aids in the form of graphical overviews of the hypertext structure. The aim of the present experimental investigation of learning in hypertext environments was to examine the impact of such graphical overviews on learning achievement in conjunction with the respective influence of individual learner variables. In a sample of N = 82 students working on a hierarchically structured hypertext about the psychology of memory, how domain-specific prior knowledge and the self-concept of computer-related ability affect perceived disorientation and learning outcomes as a function of access to a navigational aid was tested. Participants provided with a graphical overview experienced somewhat less disorientation, particularly those with high prior knowledge. A high computer-related self-concept also helped to curb disorientation. Both prior knowledge and computer-related self-concept proved to be significant predictors of complex learning achievement (i.e., the acquisition of structural knowledge). Participants with high prior knowledge, a high self-concept, and access to the graphical overview achieved better retention scores (i.e., acquired more purely factual knowledge). ********** Multimedia systems that present information as a network of nodes and links, rather than in a traditional linear sequence, have generated particular excitement in the context of learning with multimedia. Because they present material as part of an interconnected network, these hypertext and hypermedia systems are regarded as a particularly effective way of supporting self-directed learning. Hypertexts allow users to elect which links to follow, and to work their way through the material along various paths of their own (in accordance with their learning preferences, e.g., Plass, Chun, Mayer, & Leutner, 1998). Hypertext has been termed "non-sequential" (Nielsen, 1990a) or "non-linear" in structure to differentiate it from forms of text with a predetermined structure. However, it has been shown that people navigating through hypertext environments may encounter problems of disorientation (lost in hyperspace; e.g., Conklin, 1987; Edwards & Hardman, 1989; Elm & Woods, 1985) and cognitive overload that prevent them from concentrating on the content of the text and thus inhibit deeper-level information processing. Disorientation involves problems such as difficulty in gauging the scope of a hypertext, uncertainty about the route taken to arrive at the present node, uncertainty about where one is in relation to the other nodes of the hypertext, difficulty in deciding which node to move on to next, and not knowing which nodes have already been visited. Clearly, navigating through hypertext makes additional demands of the cognitive system and calls for resources that--given the assumed limitations of the working memory--may result in learning deficits (e.g., Chandler & Sweller, 1991; Kim & Hirtle, 1995; Niederhauser, Reynolds, Salmen, & Skolmoski, 2000; Tripp & Roby, 1990). To help preclude this kind of disorientation, hypertext authors often include navigational aids in their designs. As formulated in the "supplantation" hypothesis (Salomon, 1979) for media as a whole, navigational tools are of assistance to learners when they replicate the cognitive processes necessary for, or beneficial to, learning and problem solving. Ausubel (1960) proposed that conventional texts should be preceded by "advance organizers" illustrating the structure and contents of the text to follow in a more general form. Indeed, most authors regard graphical overviews of hypertext structure as indispensable navigational tools. Like tables of contents in linear texts, their function is to reproduce the structure of the hypertext, thus helping the user to construct a mental map of this structure (Simpson, 1989). …