Up: Home > Handbook > Using the Web to Teach Economics
The EDNER Project (2002a) has highlighted some issues that may undermine the value of a set of links for students. One of these is a lack of context: arranging links in one big list is much less useful than indicating how each link is relevant to the students' learning. Giving links a context might be a matter of giving an informative heading, or of presenting links in the context of a specific assignment rather than a general list.
In the case of a library catalogue or local software archive, access to a page might be restricted to your institution, so that someone accessing the site from outside - say, through a commercial service provider at home - will get an error message. If this is the case, it is important to make sure that students know this.
One way in which Web links differ from references in a paper publication is that a reference will always refer to the same thing, but the file that is at a Web address might change at any point in the future. Over time, any list of links will suffer 'linkrot' as files are moved and sites disappear entirely. Linkrot is a large factor in users' frustration with the Web. If you do not keep tabs on linkrot, you might assure students that information crucial to a particular assignment is linked from your Web site when in fact the link only gives an error.
Fortunately, there are two kinds of tool which make it easy to battle linkrot. The first is linkchecking software or online services. You feed this service the home page URL of your site and it checks all the links on all pages, reporting on which are broken. An example is Xenu's Link Sleuth, a program freely available for Windows. For Apple Macs, try Link Checker.
The other kind of tool is an archiving service. If one of your links is broken because the original owner has taken down that information, the pages may still be available in an archive. Go to the Wayback Machine and type in the (now broken) URL. You should now be able to browse a list of archived versions of that page. If the content you want is there, you can replace the broken URL with the URL of the archived site. This will work for many documents, although sometimes not for pages that are deep inside a site, and not for dynamic services such as some interactive quizzes. Alternatively, if you fear that the site will disappear completely in the near future, you may wish to copy the page to your PC and put it up on your own site (see the points on intellectual property below, however).
3.2 Accessibility issues