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Re: Issues in EU-funded ratings research project

From: Jacob Palme <jpalme@dsv.su.se>
Date: Sat, 10 Jul 1999 11:58:55 +0200
Message-Id: <v04020a02b3acc5b2152e@[]>
To: IETF Applications Area Discussion List <discuss@apps.ietf.org>
Cc: SELECT EU project mailing list <select@dsv.su.se>
At 11.08 +0200 99-05-27, Jacob Palme wrote:
> The EU-funded research project SELECT
> ( http://cmc.dsv.su.se/select ) has as its main goal to
> develop a rating system for web pages. This system will
> allow people, whenever they see a web page, to give their
> rating of this web page on a scale from "very poor" to
> "superior". The ratings will be stored in a data base, and
> people will be able to make searches of rated documents,
> such as "find all documents whose upper quartile rating is
> higher than 'good'" and has the keyword 'SMTP'" or "find
> all documents highly rated by people who often rate
> documents the same way I rate documents".
> We will try to use open standards as much as possible, so
> that people can re-place one part of our system and
> continue to use the rest of the system. For example
> re-placing the user interface, but keep the data base, or
> the reverse. Since there already is a standard for ratings,
> PICS, we will with high probability use it, where possible.

I have now been looking more at the encoding needs for
SELECT. SELECT will need a number of protocol elements
with a somewhat complex internal structure. Examples of
protocol elements needed:

Get service-           Find out which rating services are handled by
description-list       this server

Get service-           Find out which rating categories are handled by
description            this service

Send-rating            Send a rating on a resource

Register-rater         Register a rater with a server

Login                  Establish credentials for a user

Logout                 Waive credtentials for a user

Search                 Make a search for rated resources

Evaluate               Get the ratings for a list of resources

Find news              Find new resources of special interest to a
                       particular user

Exchange-ratings-data  Mirror ratings data between two SELECT servers

When I wrote my previous message to this list, I said that
we were going to use PICS as a basis, since PICS is an
already existing standard for some of the protocol elements
we need. PICS has part of the functionality we need, but
lacks the "Send-rating", "Search" and "Find news" function,
and is possibly restricted in the kind of data formats
allowed for ratings.

We are now considering another alternative, which is to use
XML for the encoding of our protocol elements. XML has some
advantages compared to PICS:

(1) There is, and will even more in the future be, much
    software available for various processing of XML-formatted

(2) XML is a neater and more readable format than PICS.

(3) XML can be extended in neater ways than PICS.

XML has also disadvantages:

(4) Unless compression is used, somewhat more characters
    are needed.

(5) When there is an existing standard, like PICS, it is of
    course an advantage to use it. Because of this, if we chose
    to use XML, we will try to make the XML encoding equivalent
    to PICS, so that we may in the future easily provide
    servers which can provide ratings using either XML and PICS.

One could of course also consider to use PICS where it
suffices, and add what PICS cannot do, using XML. But this
would not be very neat.

Can anyone give us any comments on the choice of PICS or XML
for our protocols?
Jacob Palme <jpalme@dsv.su.se> (Stockholm University and KTH)
for more info see URL: http://www.dsv.su.se/~jpalme
Received on Saturday, 10 July 1999 07:37:17 UTC

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