This first experiment was designed to provide the author with the practical experience on how the links could be augmented into a page. An educational Web site teaching cookery skills was constructed to serve as a platform for distributing the online information and also as a simple adaptive system. The cookery domain was chosen as it was relatively simple and straightforward to insert additional links which were aimed to give additional explanation, and the links could be rendered to different users based on their stereotype, beginner or advanced. Most existing Web-based adaptive hypermedia systems were created to teach universal subjects such as mathematics, medicine, computer science and so on, so this was chosen to provide an alternative, and it is also the subject known to the author.
The Web site comprised the domain model (topics concerned with cookery) and the user model (a database that stores information about an individual user, that is, name, surname, password, and user categorisation, as previously described in Section 2.3.2. The user is recommended to complete thirty multiple-choice questions, and the pre-test score identifies the user categorisation. The UK standard assessment criteria was chosen to categorise users based on their pre-test score, i.e. a threshold value of 70% was employed. If the user scores below 70%, then the user is categorised as a beginner. Otherwise the user is regarded as an advanced learner. The user can then move on to study the presented materials. Straightforward adaptation techniques were applied. Firstly, adaptive presentation was employed by means of conditional inclusion of fragments using ‘if-else’ statements which enabled decisions made on what links or content is to be displayed to the user based on the user’s pre-test result (i.e. beginner or advanced). For instance, the code shown in Figure 4-1, a very AHA-like approach using ASP, illustrates the idea of how the conditional fragments are implemented.
Figure 4-1: The use of conditional inclusion of fragments in ASP
Secondly, adaptive navigation support was put into practice by the use of adaptive link hiding (i.e. making the links appear like the surrounding text but still active) and what is termed ‘link augmentation’. As described in Section 3.3, the notion of the link service approach is that links are stored in separate linkbases and the link server enables the links to be augmented into the content page as they are viewed through the browser by the means of a proxy server.
<% // to check if the user has already taken the test %>
<% // if users have not yet taken the test then the following code is activated %>
<% If isEmpty(percentile) Then %>
<% // display one thing %>
<% // if users have already taken the pre-test and scored > 70%, the following statement is valid %>
<% elseif percentile > 70 %>
<% // display another thing %>
<% // if the user has already taken the test but scored < 70%, then this statement is valid %>
<% else %>
<% // display something else %>
Figure 4-2: The system architecture of the cookery website
Figure 4-2 describes the system architecture and how the system functions. First, a client requests a Web page embedded with ASP scripts. The request is then sent to the proxy and passed on to the Web Server – the Internet Information Server (IIS). The Web server retrieves the ASP page and invokes the ASP engine. The engine then interprets ASP code and converts it to HTML, which is in turn forwarded back to the proxy. The proxy was programmed to read and parse HTML files and communicate with Auld Linky. Auld Linky locates keywords that match a given user context (which will be explained in the next paragraph) in a set of linkbases and returns the matching URL and source keywords to the proxy. The proxy replaces the keyword with the URL, which is in turn substituted with the anchor tags. Finally, the request is sent back to the browser and the browser displays the HTML with augmented links corresponding to a given individual user. As a consequence, the user can view the original links hardcoded into the page by the author in addition to links from a linkbase provided by Auld Linky.
Database Adaptation model
ODBC
Links matched keywords
Obtains all links in the linkbases P r o x y Auld Linky Links matched keywords
Client Side Server Side
HTTP Request HTTP Request HTTP Response + Keywords replaced with <a href…> HTTP Response + Keywords Linkbases Link matching Browser
Web Server (IIS) ASP
The Web site contained nine lessons, of which five were designated for beginners and four for advanced learners, and two linkbases created as part of this experiment namely, beginnerlinkbase, and advancedlinkbase, using the aforementioned FOHM standard, where a link is defined with the keyword, type, and the destination. Links from a linkbase are inserted into the openning webpage based on the user categorisation (i.e. user’s knowledge level – beginner or advanced) from the pre-test. For instance, if the pre-test result indicated that a user was a beginner, then only the beginner’s lessons would be highlighted with shaded colour to indicate a recommendation for users to commence learning, whereas advanced lessons would appear as if they were hidden links. The user could then select the shaded beginner’s lessons which would have all the augmented links from the beginner linkbase. Similarly, if a student was categorised as an advanced learner, then advanced lessons would be actively visible (while the beginner lessons would appear as if they were hidden links) and the advanced links would be augmented in the presenting pages. Nevertheless, if the user decided not to take the direct guidance provided, and instead clicked on their preferred lesson, they would still be able to observe the links in other groups than their own categorisation. Figure 4-3 illustrates the recommended lessons for beginners shaded in yellow, whereas the advanced lessons appear neutral as if there is no link.
Figure 4-3:The recommended lessons for beginners
In summary, the first experiment enabled the author to have an understanding of how an AH system works and how the link augmentation could be implemented and integrated into an AH system. The next research question was then to investigate and expand the capability of the link augmentation technique to other AH systems.