Paper 04, ChemConf '96
| Abstract and Index | 1. Introduction | 2. Hypermedia | 3. Instrumental Analysis Prelabs | 4. Summary | 5. References |
The HTML (hypertext markup language) format of Web documents provides an easy-to-use authoring language to create hypermedia material. Using hypermedia effectively requires some thought to its characteristics to properly match the hypermedia to the intended goal. For example, a course web page is a convenient means to deliver copies of lecture notes to students for their use during class. However, the outline nature of lecture notes provides little value to someone trying to learn about a given topic from scratch. Likewise, fancy graphics are not necessary to deliver textual information such as homework due dates, and only slows down the transfer of information.
A hypertext application is a collection of documents (computer files) that contains highlighted words or phrases called anchors. These anchors define hyperlinks that lead to other documents or other sections of the same document.[16, 17] Hypermedia is a superset of hypertext that includes other media forms such as graphics, audio, and video.[18] The links in hypermedia allow random access to information, and using a hypermedia application is usually referred to as navigating or browsing.[19] A hypermedia user can click on a link and go to a new document, browse it, and return to the original document. Alternately a user can click on another link and proceed along a different path to more information. It is the reader who actively decides on the path to take through the information and how in-depth to read each document. This random access and user control is a major distinction between hypermedia applications and conventional textbooks, which are usually designed to be read sequentially, i.e., from start to finish. In print a reader can assume that the text will progress from simpler to more difficult or complex. The random access capabilities of hypermedia the disadvantage of lacking structure, as shown in Fig. 2, and can juxtapose documents of very different levels of conceptual difficulty.
Fig. 2. Unstructured Application Design
An unstructured document layout presents some interesting possibilities for experimental fiction, but would leave science students wondering if they had found everything they needed to learn. An alternative is to design an application with linear or indexed layouts, as shown in Figs. 3 and 4, respectively.
Fig. 3. Linear Application Design
Fig. 4. Indexed Application Design
The triangles at the bottom of the pages in Figs. 3 and 4 represent navigation aids that link to other documents. When used properly, they can help users retain a sense of direction as they work through a series of documents. Common navigation aids are text anchors that link to the "previous" or the "next" document in a linear series of pages, or to an index or home page. Since users might stumble into the middle of a series of documents from anywhere, it’s best to avoid phrases like "go back" or "return" in these navigation links. For an application containing a fairly small number of web pages, a complete map can be provided. The tables at the top and bottom of each page of this on-line paper indicate the current section the user is reading, and provides links to the other sections and the index. Icons of left, right, or upward pointing arrows are commonly used as navigation aids to indicate a direction or home page. Non-intuitive icons that link to a home or index page should be avoided because they assume the user has started from a beginning page and read instructions on the meaning of the special icon.
The two designs shown in Figs. 3 and 4 provide a structure for educational documents, but lose the in-context access to related material that hyperlinks provide. A compromise is to use a hybrid design with a top-level linear or indexed structure, and include hyperlinks in the text of the documents where appropriate. This conference paper is an example of a hybrid design with an indexed top-level structure. The text of the documents contains hyperlinks, such as the examples of the course home page and the computer dry lab in Section 1. If you went very deep into the examples you probably needed to hit the back arrow several times to return to this paper, and might have felt rather lost. To help users from getting lost, written or classroom instructions can be provided, such as suggestions that they use the browser's back arrow to return from linked material, or that they bookmark the index page.
The take-home message from the above discussion is to select a design that matches the content and goals of your material, and provides as much structure as possible. For delivery of class notes or lab instructions, a simple linear or indexed design might be most appropriate. Tutorials on difficult concepts might require extensive links to remedial documents or multimedia material. In general the simplest design that does the job will be the most effective.
| Abstract and Index | 1. Introduction | 2. Hypermedia | 3. Instrumental Analysis Prelabs | 4. Summary | 5. References |
http://www.chem.vt.edu/archive/chemconf96/2hypermedia.html, updated 5/29/96
Copyright © 1996 by Brian M. Tissue, all rights reserved.
This page is maintained on the Virginia Tech Chemistry Department webserver. Comments, suggestions, and questions should be directed to Brian Tissue at tissue@vt.edu.