Discrepencies in Reporting of Stats - Webtrends

Why are my numbers different?

[DavidAtWork]

Hello all,
I have been using webtrends for quite some time now (to generate reports) but am just really starting to look at the data its providing. (Normally , I leave the research of the data to marketing). The questions I am beginning to ask myself now about logs and analysis has led me to this site. I have learned more in 2 days here than I have in a long time searching the net for info.

My question is...Why do I see two different sets of numbers when I generate reports from the same logs? (ex. I run a YTD report broken down by months, then I run a 1 month report and try and match up the data) Visitors are off by 10-20 or so etc. that type of thing.

Many thanks in advance for any replies...

[vrtlw]

Visitors are off by 10-20 or so etc. that type of thing.

I haven't used webtrends in a while now, but are the visitors you refer to unique visitors for the period?

If so they would cetainly be different, as some could re-visit your site, say in 6 weeks time. How do your hits and page views compare?

[DavidAtWork]

Thanks for the reply....
Take Visitor Sessions for example. If I run a montly report for say Dec. 03 Then run a ytd report by months for all of 03 and take the Visitors sessions for Dec. from the YTD report and compare it to the Visitor Sessions from the single monthly Dec. 03 report. They don't match up. I would think they should since its pulling from the same logs and from the same profile. I don't think its the biggest deal in the world as I realize this is not an exact science as it were. But I know someone is going to be asking me the question. The numbers are not that far off. Maybe a dozen or so.

thanks...