Tutorial: TM Semantic Visualisation (Part III)
(continued from Part II)
The landscape we looked at last time only consisted of mountain ranges and valleys made up by the intensity and extensity of certain words (or word groups) within a set of documents. Documents which are all captured with a topic map.
Where Are The Documents?
One interesting question is how documents fit into the landscape: Every document can be characterized by the intensities of the words within it. And this very intensity can be interpreted within the map.
In the picture above every circle corresponds to one document. The position of the circle marks the best fitting place for the document. The size of a circle signals the uncertainty of the position. The larger the circle the less precisely a position can be called home.
This idea I copied from SOMs (self organizing maps). In real-world maps, though, there may well be several "best" positions for one particular document. More about that later.
Ok, But What Documents?
Seeing the document positions lining up the major landscape features is fine, and it helps to understand how the landscape is formed, but in the end the user wants to
- see a preview of the document, and
- then have full access to it.
For this purpose I created a bit of HTML and jQuery code:
When you move the mouse over one of the circles, a window with terms will fade in. The terms in it are ordered by relative importance within the document, with the most frequent first. You will notice that if a document is placed along a prominent site, the first term(s) will match the terms of the site.
If you are interested in the full document, you can activate the link (read: you click). But as all my documents currently live inside the synthetic topic map, I just use a fake link for the moment.
You can play around with it yourself. It seems to work in Firefox and Safari but may need more love (resp. hate) for other browsers.