You can have a look at our announcement page which contains a "Usenet
timeline" of especially memorable articles and threads. We want to thank
the many users that contributed to this timeline. Special thanks go to
Andrew Tannenbaum, Brad Templeton, James "Kibo" Perry and Rob
Pike. Their insights into the history of Usenet were invaluable to us.

http://www.google.com/googlegroups/archive_announce_20.html

We have also received several inquiries about:

- The comprehensiveness of our new 20 year archive
- More information about the individual archives we merged together
- Various statistics about the new 20 year archive

The remainder of this post should help satisfy your curiosity. :-)

Time ranges covered by the different archives that we merged together:

1980's                     1990's                        2000's
1  2  3  4  5  6  7  8  9  0  1  2  3  4  5  6  7  8  9  0  1  ...
 uuuuuuuuuuuuuuuuuuuuuuuuuuuuuuu nnnnn     ddddddddddddddddd
                          cccccccc   ccccccc               gggg...

More information about the individual archives:

u: The famous UT-Zoo archives. These were created by Henry Spencer
   at the University of Toronto, Department of Zoology. They have
   been extracted from the old 9-track tapes by David Wiseman, Bruce
   Jones and Henry Spencer with the help of many others. These
   archives are spotty in the non-tech field the further they
   progress in time because the archival system could not handle the
   increasing traffic of Usenet. Henry had to become more and more
   selective over time. Nevertheless, these are the most valuable
   and breathtaking archives to many of us. :)
n: Kent Landfield provided us with the complete NetNews 'Usenet on CDs'
   collection. These archives are comprehensive for US hierarchies and
   some international hierarchies.
c: We were about to build the extended index with gaps because we
   thought there were no more comprehensive old archives to be found
   (we started "archive hunting" over a year ago). But fortunately
   Juergen Christoffel turned out to be our savior at the last minute -
   well, rather the last three weeks - in which he worked tirelessly
   for us to extract his archives from Exabyte and DAT tapes to fill
   remaining gaps in coverage.
d: These are the archives that were part of Deja's assets which we
   acquired in Feb 2001. All these have been available at
   deja(news).com at some point. The coverage is comprehensive
   except at various intervals (lasting between a day and a week).
   The coverage for international hierarchies is also spotty for the
   first few years.
g: We started archiving in Aug 2000. Our archives are comprehensive
   for both US and international hierarchies.

Number of articles per year (roughly):

1981:       4 000 (from May 11)
1982:      27 000
1983:      62 000
1984:     108 000
1985:     158 000
1986:     101 000
1987:     117 000
1988:     185 000
1989:     480 000
1990:   1 203 000
1991:   2 085 000
1992:   9 920 000
1993:   8 011 000
1994:  14 737 000
1995:  21 064 000
1996:  52 635 000
1997:  80 044 000
1998: 107 063 000
1999: 129 113 000
2000: 132 585 000
2001: 149 808 000 (through Dec 20)

We estimate that our total coverage of Usenet is very close to "complete
as can be." We searched long and hard for more old archives to fill in
for remaining "spottiness" (e.g., more non-technical posts from the late
80s, more coverage of the earlier history of some international
hierarchies, archives for the first two years of Usenet - 1979 and 1980)
but we were not able to locate any yet. Currently we believe that no
other comprehensive archives exist anymore, but we would love to be
convinced otherwise :-)

We are aware that there are many small collections of Usenet articles
that were saved by many dedicated individuals in the Usenet
community. Please understand that we cannot undertake the gargantuan
task of merging these with our existing archive.

If you need more information on how to use Google Groups:

http://groups.google.com/googlegroups/help.html

The best way to rummage through our old archives yourself is to use
specific date ranges on the Advanced Groups Search page:

http://groups.google.com/advanced_group_search

If you have any comments about Google Groups, you can send them to:

groups-supp...@google.com

Thanks,
The Google Groups Team