Navigational Principles in Multimedia Learning
From Eduwiki
The role of navigational aids in the comprehension and the use of complex hypermedia. Information resources play an increasing role in learning. Students in secondary and higher education are asked to write reports and do assignments using multiple sources of information. This presentation is about the effects of navigational aids on learning from complex text, both in print and computer based system. Textbooks. Hypertexts and multimedia documents are examples of complex texts. It has been shown that structural properties of texts play important role in the comprehension of texts. They are easier to understand when they are organized according to standard schema, using structured threads or signaling devices, such as headings, outlines and introductory sentences. There is extensive research just on the use of headings in texts. Some suggest that headings artificially focuses the readers attention on detail information, others show how headings decreases the frequency of regressive eye fixations. Further experiments indicate that headings speed up the activation of word meaning from memory. The author notes a lack of research regarding the effects of more global content representations, such as tables of contents, concept maps and flow charts. The lack of research is striking since many users make their way through dozens of pages using content representations before they can access and read relevant materials. Some evidence suggests that global content representations are also essential in helping readers make sense of complex texts. They are especially useful for readers to decide which parts of the complex document are relevant to his or her task.
Verbal content representations in hypertext systems Hypertext can be broadly defined as database of textual units or pages connected through links. Hypertext is a nonlinear networked information with no predefined path. In hypertext it is up to the reader to navigate through pages by selecting the links available, as a function of their need. It is even more crucial to assist navigation in hypertext than in printed document. Early hypertext studies found that users were often disoriented. It became evident that lack of explicit structure was a problem. Embedded vs explicit linking of information pages Designers of hypertext system may either present links in a list separated from the actual page content, or embed links within content. Some studies have found mixed results but overall there is positive evidence in favor of embedded links. They save screen space and preserve the semantic context in which the links appear.
The breadth-depth trade-off in hypertext menus. Menu structures and their effects on the user has been a subject of many studies. In these studies it was found that the two level menu resulted in a faster location of targets compared with three or more levels. The menu depth seems to increase the users feeling of complexity. Grouping and expandable menus The pull-down menus that that maximize the visibility of intermediate categories was the most effective.
Concept maps Cover pages, tables of contents and concept maps play the role of advanced organizers. In a study they manipulated the organization of the table of content, by listing documents in an order consistent with the story and document types and in scrambled order. Even though individual document in their hypertext systems were self contained, the structured table of contents seemed beneficial to most. In concept maps the benefits seem to be a function of how they are designed. The amount and type of links they display. While a hierarchical list or map can benefit a low knowledge student, the network map could hinder their learning.
Conclusion Hypermedia and other online information systems are becoming more and more widely used. Whether at home, school or workplace people access a huge database of information. Providing guidance to the user is a challenge for designers of hypermedia systems. Because of the flexibility of hypermedia systems can be structured in many different ways. Thus the quality of content representation and user guidance devices is a critical prerequisite to the usability and effectiveness of hypermedia system.
