<title>CyberMaps from Peter Gloor</title>
<h1>CyberMaps</h1>
Peter Gloor is a postdoc working at MIT until Sept 92.
He has various hypertext-related projects, including a multimedia
CDROM conference proceedings, and the CyberMap project.
<p>
A cybermap is a map of connections between documents
(or parts of large documents)
which he builds by looking at text alone.
He builds a keyword vector for each document,
and then generates a "similarity" matrix for each document pair.
(See his paper for the algorithms.)
Keywords are weighted by their power to distingish documents.
<p>
Given the list of similarities, he uses a fast and simple method
to arrange the documents first into clusters, then into one big
tree, the minimum spanning tree for the similarity matrix.
This algorithm involves using the (similarity, doc1, doc2)
triples in order of descending similarity
to make a links between  related documents.
He limits the links to one per document
to avoid getting a mess. When every document has exactly one link,
there are a number of separate trees which are his clusters.
He then links the clusters, starting with the one created last
(and therefore having the weakest links), finding the strongest
similarity between documents in that and some other cluster.
The result is a single tree. He picks as root node the document
which had the highest weight of interesting words.
<p>
Peter has tested his work on a simple catalogue of dinosaurs,
using a Macintosh, and on a set of 50 documents using
MIT's Connection Machine. He uses large quantities of computer
power to generate the similarity matrix.
<h2>Maps of the Web?</h2>
I suggested that it would be neat to produce cybermaps
of the W3 documentation. We would then have three forms of
organisation involved: the directory structure in which
we placed the documents, the explicit links, and the similarity
list from the textual content. Peter went away with a list
of suitable hypertext documents
(The 716 documents in hypertext/*, the 414 in hypertext/WWW/*, or the
32 in hypertext/WWW/DesignIsssues/*. He will probably try
the 32 first!)
<p>
Peter has also used his system on mail messages and news articles.
It is unfortunate that it's not very easy to incrementally
add new material. This could be an interesting sort of tool
for generating a browsable intelligible web out of
a mess of mail, news and random documents.
<address>Tim</address>
