Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Path: utzoo!linus!philabs!cmcl2!seismo!columbia!garfield!eppstein
From: eppstein@garfield.columbia.edu (David Eppstein)
Newsgroups: net.news,net.news.group
Subject: more interim results from worldwide net readership poll
Message-ID: <1425@garfield.columbia.edu>
Date: Tue, 25-Mar-86 15:46:51 EST
Article-I.D.: garfield.1425
Posted: Tue Mar 25 15:46:51 1986
Date-Received: Sun, 20-Apr-86 11:51:26 EST
References: <5192@glacier.ARPA> <1994@hao.UUCP> <5249@glacier.ARPA> <1998@hao.UUCP> <1165@utcs.uucp> <5641@glacier.ARPA>
Organization: Columbia University CS Department
Lines: 29

In article <5641@glacier.ARPA> reid@glacier.UUCP (Brian Reid) writes:
> ... The definition of "Person X reads group Y" is that person X's .newsrc
> file shows that he has read (or marked as read) at least one message in
> group Y that has not yet been expired. If "expire" is run with standard
> options, this means that person X has read at least one message in that
> newsgroup in the last two weeks. If your site expires more rapidly than two
> weeks, then a more stringent test will be applied. 

This brings up a problem with this survey that I have been wondering
about for a week or so.  Some groups have very low volume, such that
it is possible for no articles to be current in the group when the
survey is run.  If that were the case, the survey would show no
readers when in fact many people may read the group.

As a practical example, one of my favorite groups happens to be
net.roots.  We expire news weekly, and in many weeks there are no
messages in net.roots.  Yet I would object very strenuously to being
called a non-reader of the group.

A possible solution would be to also count people who have caught up
entirely with a group even if there is no message left unexpired in
that group.  This would still have some inaccuracies, but they would
perhaps be counterbalanced by the people who haven't yet bothered to
unsubscribe to the groups because they are so low volume.  Perhaps the
survey already does this, but there is no indication of that in the
included description.
-- 
David Eppstein, eppstein@cs.columbia.edu, seismo!columbia!cs!eppstein
(note that the garfield in my headers is *not* the one in the UUCP map)