Most library thesauri are a graph-like structure where each node may have relations to broader terms, narrower terms, related terms, equivalent terms, preferred terms, and such.
The current thesaurus results page in OpacOnline lists all items in these categories, if applicable for the term. Each item that's listed is a hyperlink to that particular thesaurus term. Another link provides a direct query into the catalogue for records containing this thesaurus term in their keywords. The number of catalog results that the user will receive is already avaible.
You can see a picture of OpacOnline's thesaurus results, on the NiZA library's site, below. All information from the thesaurus is there, clearly and concisely displayed, easy to understand and inviting to click around to see more of the thesaurus.
However it may also be a nice idea to present the structural information in a more graphical way. At OpacOnline we are considering to do this for the next release, OpacOnline 2.1, scheduled for August 2007. Currently we are investigating what options would be good for this.
Few implementations of a graphical thesaurus representation exist; one attempt has been made by the company Gridwalker. You can see their solution in the screenshot below. We are not impressed -- the page is crying out ugly, the site uses the proprietary Flash technology, and we find literally nothing appealing here. This is how OpacOnline will certainly NOT do this !
Another story is the solution provided by the AquaBrowser software. In the screenshot below you can see a nice graphical structure to the left of the page. It is updated dynamically when you click on any of the related items, which upon clicking, move to the center, and the surrounding graph is updated. Very nice indeed ! The only negatives that we find with this is that again, it has been implemented in the proprietary Flash format, and that their solution appears to require Microsoft server software.
At OpacOnline we are considering something like the AquaBrowser solution above, but of course using our trademark methodology of open source and open standards. Our solution will be pure XHTML / Javascript, no Flash, no applets, or such. Various open source Javascript libraries exist for displaying nodes of graphs, that should facilitate our development effort; we are currently looking into Aslak Hellesøy and Dave Hoover's implementation, as well as into open-jACOB's.
If you have any suggestions, wishes or other remarks on this subject please do share with us !
