Errors in Datestamps and Etags
Indicating Change
10.7%
32%
redundant crawl
0.30%
0.087%
missed change
Datestamps
Etags
L. Clausen, “Concerning Etags and Datetsamps”,
4th International Web Archiving Workshop, ECDL 2004
http://www.netarchive.dk/website/publications/Etags-2004.pdf
40.1 % of pages without Etags
0.07% of pages without Datestamps