Hypermedia has been gaining much attention over the past two decades. As a learning environment it has changed the way we communicate and learn. The purpose of this paper is two-fold. First, it is to present an overview of relevant research from hypermedia literature regarding its history, definitions, features, problems, constructive hypermedia, and constructivism – a theory that supports hypermedia so as to generate a better understanding of hypermedia for meaningful learning. Second, it is to briefly discuss the suggestions for future research in the field of hypermedia through literature review so as to help set a direction for those who are interested in hypermedia research.

INTRODUCTION

Over the past two decades the Internet's pervasive influence has affected communication and learning in a way that can hardly be underestimated. It has changed the way we present, format, and share information. The Internet can be both used as an instructional medium as well as a delivery medium. As an important component of educational technology, hypermedia is an information retrieval and instructional environment that supports active learning. However, simply providing an advanced presentation system or a more elaborate information storage and retrieval system does not guarantee more effective or efficient learning (Palumbo & Bermudez, 1994). To take advantage of the instructional capabilities of the Internet, we should not only use it as a simple delivery medium for information.

The purpose of this paper is two-fold. First, it is to present an overview of relevant research from hypermedia literature regarding its history, definitions, features, problems, constructive approach in hypermedia application, and constructivism – a theory that supports hypermedia so as to generate a better understanding of hypermedia for meaningful learning. Second, it is to briefly discuss the suggestions for future research in the field of learning with hypermedia through literature review so as to help set a direction for those who are interested in hypermedia research.

More in detail, this article has the following organization. The following section presents three pioneers in the history of hypermedia. Then, the author discusses its definitions, features, problems associated with hypermedia, constructive hypermedia, and constructivism – a theory that supports hypermedia. Finally, the last section provides a conclusion and discusses suggestions for future research in the field of hypermedia.

HISTORY

In the history several pioneers have contributed to hypermedia. Vannevar Bush is the first person to realize the potential of storing information with built-in associative links to other data. In 1945, Bush had his article As We May Think published in the Atlantic Monthly. He proposes a powerful mechanical device called Memex that would extend the power of human mind. His Memex is a desk-like device that contains viewing screens, buttons, levers, and a keyboard. It could store almost anything, including books, pictures, periodicals, and newspapers. Believing that the human mind operates by association, Bush argues that the search and retrieval of information should be based on association rather than indexing. He states: “ It is exactly as though the physical items had been gathered… from widely separated sources and bound together to form a new book. It is more than this, for any item can be joined into numerous trails” (Bush, 1945, p. 107). Though he never built a real Memex, Bush’s idea of such a system is a driving force in the development of hypermedia.

Being another pioneer who has significantly contributed to hypermedia, Engelbart is credited with many inventions including the mouse, multiple windows, electronic mail and teleconference. Following Bush’s idea of associative linking and hoping to augment human intellect, Engelbart developed and implemented the first hypertext system, NLS(oN Line System), in 1960s at Stanford Research Institute. Ted Nelson invented the terms “hypertext” and “hypermedia.” Echoing Bush’s Memex, Nelson points out that the value of hypertext lies in its similarity to the way we think. He has been devoting many years to his Xanadu project, a system intended to link together the sum of the world’s knowledge in text, pictures, video and sound which can be accessed by anyone anywhere.

DEFINITIONS

In the years following these visionaries, many definitions of hypertext have been proposed. First coined in 1965, hypertext was defined as “non-sequential writing” by Nelson. In Nelson’s view, hypertext is free from the constraints of sequence imposed by printed books. Conklin (1987, p. 32) describes hypertext as “… a computer-based medium for thinking and communication.” Marchionini (1988, p. 8) states that hypertext “describes the electronic representation of text that takes advantage of the random access capabilities of computers to overcome the strictly sequential medium of print on paper.” Hypermedia “extends the nonlinear representation and access to graphics, sound, animation, and other forms of information transfer” (Marchionini, 1988, p. 8).
Heller (1990) describes hypertext as “a nonlinear database with tools for selecting information from the database and presenting the information to the user” (p. 431). Carlson (1990) describes hypertext as “nonlinear prose, interactive print, or dynamic text using electronic capabilities to overcome the limitations of linear, printed text” (p. 16).

Nodes and associative links are the basic elements of all hypertext system (Jonassen, 1989). Nodes are the basic unit of information in a hypertext. Marchionini (1988, p. 8) describes nodes as “the information units” such as paragraphs, images, articles, individual lessons, etc. In a similar way, Jonassen (1989) defines nodes as “information fragments,” which may be in the form of text, graphics, video sequence, audio sequence, and windows. He points out that the most popular metaphor for nodes are “note-cards.” It implies that hypertext nodes may be accessed in any sequence that meets the information needs of the user in the same way as note-cards.

Links enable the user to determine the sequence in which the information is presented. Conklin (1987) points out that links are the essence of hypertext as they facilitate jumping from one node to node in a non-linear way. According to him, there are two types of links – referential links and organizational links. Referential links connect a source in the current node to a referent in the destination node. Organizational links connect a parent node to its children in a tree fashion. Links are the relations that connect nodes, and links can be both explicit and implicit (Marchionini, 1988). Explicit links are “used by authors to suggest paths… through the information. ” Implicit links are used to “support materials such as dictionaries and encyclopedias as well as navigational aids such as graphics of the user path and guided tours for the learner.” These dynamic links “offer learners individualized access to rich intellectual environment” (Marchionini, 1988, p. 9). Kearsley (1988, p. 21) points out: “The more links contained in the documents, the richer the connectivity of the hypertext database.”

FEATURES OF HYPERMEDIA

Some researches detail the features of hypermedia and its relationship with learning, including Kearsley (1988), Marchionini (1988), Dear (1988), Jonassen (1989), and Carlson (1990). Kearsley (1988) notes that from the earliest literature on hypertext, the proposition that hypertext matches human cognition has been emphasized. The associations provided by links in a hypertext system “should facilitate remembering, concept formation, and understanding.” He said: “Hypertext should improve learning because it focuses attention on the relationships between ideas rather than isolated facts” (p. 23).

Marchionini (1988) discusses the great potential of hypermedia systems for learning and teaching. According to Marchionini, hypermedia makes it possible to store huge collection of information in various media forms in a very compact form and such database can be accessed easily and rapidly. In addition, hypermedia provides the potential to change the roles of teachers and learners and the interactions between them. Furthermore, hypermedia is an enabling environment rather than a directive one. He wrote: “Not only does hypermedia offer a new way to learn course content, but also it offers new ways of learning how to learn.” Hypermedia environment requires learners to constantly make decisions and evaluate progress, so it forces students “to apply higher order thinking skills” (p. 9).

Dear (1988) argues that hypermedia is a successful learning environment based on Bruner’s three types of mental representation. Enactive representation includes clicking and dragging the mouse. Iconic representation includes using the screen icons and other graphic representations. Symbolic representation includes using onscreen text and learner-produced hypermedia program.

According to Jonassen (1989), hypertext possesses some or all of the following features:
• Nodes or fragments of information
• Associative links between the nodes
• Network of ideas formed by the link structure
• Organizational structure that describes the network
• Ability to represent explicitly the structure of information in the structure of hypertext
• Dynamic control of information by the user
• High level of interactivity with the user
• Database-like structure for storing information
• Multi-media information environment (hypermedia)
• Multi-user access to the information
• “Learning is a reorganization of knowledge structures” (Jonassen, 1989, p. 23).
In Jonassen’s view, the organizational structure of hypertext mimics the organizational structure of human memory. The organizational structure of hypertext may reflect the organizational structure of the subject matter or the semantic network of an expert. If the information is stored in the hypertext in an organized way, it will be easier for the user to retrieve or find it.

Carlson (1990) points out a new metaphor for hypertext: the round book, an n-dimensional, interactive environment whose features suit the needs and sophistication of the user. While square books, a metaphor for printed books, are thoughts printed in sequence, the round book is a rich environment to be traversed, manipulated, and experienced. Carlson presents five gains made possible through hypertext implementations. First, nodes and links enable hypertext systems to organize unstructured information in both hierarchical and non-hierarchical ways. It has the potential to make implicit knowledge structures explicit. Second, hypertext systems can provide users an easy access to a large collection of information. Third, hypertext systems are problem exploration tools. The heuristics learned in hypertext projects is likely to transfer to other more demanding situations. Fourth, hypertext systems support collaborative learning. Learners have more interactions with their peers in hypermedia learning environment. Finally, hypertext environment cannot only make users learn knowledge, but also learn how to learn. It fosters users’ higher order thinking skills.

PROBLEMS ASSOCIATED WITH HYPERMEDIA

While hypertext promises great potential for learning, some problems also exist for users. The most well documented user problems include disorientation (Conklin, 1987; Heller, 1990; Jonassen, 1989; Liu, 1994; Marchionini, 1988; McDonald & Stevenson, 1999), cognitive overload (Conklin, 1987; Jonassen, 1989; Liu, 1994), and learner control (Jonassen, 1989; Liu, 1994). Many hypertexts consist of thousands of nodes, and users may easily get lost in such systems. Marchionini (1988) identifies two causes that lead to this disorientation. One cause of disorientation is the quantity of information to which a user has access. The other cause is the medium’s lack of physical feedback about quantity or scope. When users gain more experience with the medium and designers use common-sense interface designs, the problem of disorientation might diminish. The problem of disorientation or getting lost is caused by the interaction of two factors (McDonald & Stevenson, 1999). First, hypertext users must carry out several tasks at the same time: navigational tasks, informational tasks, and management tasks. Navigational tasks mean the planning and execution of routes through the hypertext.

Informational tasks involve reading and understanding the text content. Management tasks involve the coordination of navigational and informational tasks. The second factor is the “keyhole phenomenon,” which means only one hypertext node can be viewed at any one time, leaving the rest of the documents hidden.

The greater numbers of learning options available to learners place increased cognitive demands upon the learners. Browsing hypertext places significant demands upon the user. Users are presented with so much information that their brain burst with cognitive overload. While reading through a document, users must constantly make choices about which links to follow and which to ignore. Dede points out: “The richness of non-linear representation carries a risk of potential intellectual indigestion, loss of goal-directness, and cognitive entropy” (as cited in Jonassen, 1989, p. 45). Effective users need what Jonassen (1989) called “meta-cognitive strategies” to understand information, integrate information, and synthesize information. “Using a hypermedia system requires a new type of literacy (i.e., hypermedia literacy) to handle such an environment effectively” (Liu, 1994, p. 296).

As an instructional strategy, learner control permits the learners to make decisions about type and amount of instructional support they need. It enables instruction to be more interesting and meaningful to learners. Because of the quantity of information stored and the interactivity nature of hypertext, a hypertext environment demands great responsibility upon learners. Unfortunately, the research shows that not all learners can benefit from more learner control provided by a hypertext environment (Jonassen, 1989). “The characteristics of learner control in hypermedia seem both a blessing and a curse” (Liu, 1994, p. 296).

CONSTRUCTIVE HYPERMEDIA

Several researchers have recommended the constructive approach to instructional hypermedia (Joyce, 1988; Nelson & Palumbo, 1992; Palumbo & Bermudez, 1994; Jonassen & Carr, 2000). This approach to the applications of hypermedia stresses the learners’ active and creative interaction and their control of the learning processes within the system. According to them, knowledge is actively constructed by the learner rather than taught or transferred intact through the use of cognitive tools.

Michael Joyce (1988) distinguishes between two types of hypertexts: exploratory and constructive. He defines exploratory hypertext as “a delivery or presentational technology.” “Exploratory hypertexts encourage and enable an audience… to control the transformation of a body of information to meet its needs and interests” (p. 11). In an exploratory hypertext environment, the user only remains as the audience to explore or browse information, and the jobs of reader and author are separate and different.

In contrast, Joyce (1988) defines constructive hypertext as “an invention or analytic tool.” “Constructive hypertexts require a capability to act: to create, to change, and to recover particular encounters within the developing body of knowledge” (p. 11).

Constructive hypertexts move beyond simple information delivery. They allow the users to create knowledge base and share their understanding with others. The distinction between reader and author is blurred. In Joyce’s view, exploratory hypertexts are merely designed for audience, but constructive hypertexts are designed for scriptors who use hypertexts as a tool to develop their knowledge. Constructive hypertexts make us know ourselves and become authors of our learning.

Nelson and Palumbo (1992) contend that hypermedia applications will not be necessarily used to their fullest potential as instructional environments when learners are only exploring or browsing. They discuss three types of hypermedia systems used in education: knowledge presentation, knowledge representation, and knowledge construction. Knowledge presentation systems are electronic libraries that can be searched or browsed. In such systems users follow links established by authors.

Knowledge representation systems often use maps or graphic browsers to make relationships between information nodes explicit. Knowledge construction systems stress learners’ direct interaction with information and construction of personalized knowledge through experiences. It may include learner authoring, annotation and linking of information. According to Nelson and Palumbo, simply presenting information on a computer screen does not guarantee the adequate and complete knowledge transfer to learners. Instead, knowledge construction systems reflect an alternative philosophy of instruction and learning. It suggests that learners actively engage in personal and constructive process of sense making when they encounter new information.

Palumbo and Bermudez (1994) also argue that students need to actively involve in the learning process so that they become the “builders of knowledge, inherently challenged to create new insights from the information provided” (p. 185). According to them, it is not sufficient to only present information on a computer screen. They wrote: “Simply providing an advanced presentation system, or even a more elaborate information storage and retrieval system that parallels the way the human brain represents knowledge, does not guarantee that more effective or efficient learning will occur” (p.175). “A more constructivist environment - where the user not only browses the information base but also has the ability to build additional nodes and links holds more promise to promote learning” (p.175). They suggest that without the reader’s active attention and participation, the hypermedia is not a challenging one.

Jonassen and Carr (2000) argue that hypermedia construction can be used as a type of powerful mindtools. Mindtools are knowledge construction tools that learners learn with, not from. In such knowledge construction process, learners function as interpreters, organizers, and designers of their personal knowledge. Mindtools are computer software applications, such as semantic networking programs, microworlds, and hypermedia authoring, which enable learners to represent what they have learned.

“Using computers as mindtools enables learners to think in ways that they otherwise would not and could not” (p.167). In their views, hypermedia systems have traditionally been used as information retrieval systems through which learners only search or browse information. Actually, learners may construct their own hypermedia knowledge bases that reflect their own understanding of ideas. Constructing hypermedia programs engage more creating and thinking skills such as elaborating, imaging, and complex designing and planning skills than most other mindtools. Hypermedia construction is probably “the most compelling mindtool for most learners” (p. 185).

CONSTRUCTIVISM

Theories that support constructive hypermedia as a useful learning tool may include constructivism, constructionism, cognitive flexibility theory, schema theory, dual code theory, situated learning, and knowledge as design. It is impossible to discuss all the theories in this short paper. Therefore, constructivism will be focused instead in this section. Educational constructivism is a theory about learning and teaching. The principal claim of constructivism is that “knowledge is made rather than found” (Bredo, 2000). The most important epistemological assumption of constructivism is that meaning is a function of how the individual creates meaning from his or her experiences.

Constructivists believe that what we know is internally generated by the individual rather than received from any external source. Radical constructivists, such as von Glasersfeld (1995), believe that there is no objective reality that is independent of human mental activity. Personal worlds are created by the mind, so no one world is any more real than any other. Meaning-making does not rely on correspondence to the world but rather is dependent upon the understanding of the learner. All constructivists believe that the mind is instrumental and essential in interpreting events, objects, and perspectives on the external world, and that those interpretations comprise a knowledge base that is personal and individualistic (Jonassen, 1992).

Bredo (2000) discusses two implications of constructivism: (1) a concern for students’ having an active role in learning, and (2) their being allowed to redefine or discover new meanings for the objects with which they interact. Learning is an internal process and learners actively construct their own understandings or meanings. Knowledge is not a mere copy of the external world, nor is knowledge acquired by passive absorption or by simple transmission from one person such as a teacher to another such as a student. In sum, knowledge is made, not acquired (Philips, 2000).

To be more specific, constructivists think of learning as an active process. The learners have a will and a purpose in their learning. The teachers focus on learning rather than teaching and they accept learner autonomy. Learning is contextualized. Learning is related to our prejudices, fears and the rest of our life. Learning is a social activity as well. Learning involves language, involves learners in real world situations.

Constructivists encourage dialogue between students as well as between student and teacher. They strongly support cooperative learning. Constructivists focus on understanding and performance rather than memorization and exams.

Constructivism is one of the theories that support hypermedia-based learning environment. According to McDonald and Stevenson (1999), hypermedia users need to manage several tasks at the same time, which has been classified into three categories: navigation, information, and management. Navigation refers to recognizing and choosing between links. Information refers to reading and understanding. Management refers to the coordination of navigation and information. The major metaphor of hypermedia is “criss-cross landscape (Spiro, Feltovich, Jacobson, & Coulson, 1992),” with its suggestion of nonlinear and multidimensional traversal of the complex subject matter. One important principle of constructivism is that knowledge is actively constructed by a thinking person rather than passively received by the learner. The learner’s active participation in the learning process, which is recommended by constructivism, corresponds well with the learner’s tasks demanded by hypermedia.

Furthermore, a hypermedia project is often conducted in groups or in collaborative learning, which is highly supported by constructivism, particularly social constructivism. One notable principle of constructivism is that social interaction is very important in the construction of knowledge. Learning is a social activity, in which the learners negotiate meanings through collaborative interactions with others. Vygotsky (1978) states that any function in the child’s cultural development appears twice or on two planes. First it appears on the social plane, and then on the psychological plane. He proposes that every child has two developmental levels --- actual developmental level determined by independent problem solving and potential level determined by problem solving under adult guidance or in collaboration with more capable peers. The difference between the two is the zone of proximal development. With others’ help, human beings can always reach a higher potential developmental level, which will turn out to be the new actual developmental level. In project-based learning the learner can reach a higher potential developmental level with the help of other group members.

CONCLUSION

This paper has presented an overview of relevant research on hypermedia’s history, definitions, features, problems, constructive approach in hypermedia applications, and a theory that supports hypermedia learning environment - constructivism. It shows that hypermedia is not only a new system to present, store and retrieve information with its own advantages and disadvantages, but also a knowledge construction tool that enables students to learn actively and creatively. To make full use of the Internet, hypermedia, particularly constructive hypermedia, should be promoted for active and meaningful learning.

Knowing that constructive hypermedia is a useful tool for meaningful learning, you might wonder what we can do to maximize students’ learning and facilitate their achievements through a further research in the future. Chen and Dwyer (2003) provided us four suggestions as a guide for future research in the field of hypermedia. First, future research should focus on assessing relevant students’ learning outcomes that not only include declarative knowledge but also procedural knowledge and higher order thinking skills. Second, future researchers should develop reliable and valid instruments for measuring students’ performances in hypermedia learning, and research design should be grounded in existing research base. Third, hypermedia design should reflect established instructional theories such as elaboration theory and cognitive flexibility theory. Finally, future studies should consider learners’ prior knowledge and varied learning styles. I hope these suggestions can lead those of us who are interested in hypermedia to further researches that will bring about a better design, development, and implementation of hypermedia environments to foster learning.

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