posted this on October 25, 2012 02:42 PM
During processing, Angelfish looks for agf.gif requests in the log and uses hit data to calculate visitors / visits / pageviews / etc. The AGF method is further explained in this article:
The UGA tracking method is able to generate reports from the __utm.gif requests generated by Urchin or Google Analytics tracking code. One of the many ways this tracking method can be used is to "migrate" data from Urchin to Angelfish. If you have log files that contain __utm.gif requests, simply reprocess them in Angelfish!
UGA can also be used by Google Analytics customers that keep a local copy of __utm.gif requests (via the _setLocalRemoteServerMode() function). Configuration instructions are here:
Many websites automatically assign a session cookie to each visit. The cookie contains a unique value and expires when the visit ends. Here are some examples of common session cookie names:
When using the SID tracking method, you need to specify the name of the session ID cookie. During processing, Angelfish looks for this cookie name and uses the unique ID to differentiate between visits.
USR: Username Tracking Method (log-based)
If your website stores a username in a cookie or in the username log field (IIS sites sometimes do this), the USR tracking method will utilize the username to identify unique visitors. The USR tracking method is also able to track unique visitors across multiple devices - the username is the visitor ID (no tagging required)!
USR is ideal for Intranets, SharePoint websites, and homegrown or commercial web applications that require authentication (CRM, ERP, Oracle, Siebel, Hyperion, etc.).
IPUA: IP Address + User Agent Tracking Method (log-based)
The IPUA tracking method has been used by web analytics products since approximately the late 1990's. It works...but it's inaccurate.
Every device that visits your site has an IP address and a user agent. During processing, Angelfish uses each unique IP address & user agent combination to calculate visits.
There are number of issues with IPUA:
IPUA tends to treat spiders and robots as legitimate traffic
IPUA is not recommended for high traffic sites
Common Internet devices like proxy servers and NAT devices cause accuracy issues
We recommend using the "Ignore Inflated Visits" feature when IPUA is used. (it's enabled by default, max pageviews=100)
IP: IP Address Tracking Method (log-based)
The IP tracking method is ideal for logs that use the CLF format, e.g. the Google Search Appliance log file. During processing, Angelfish assigns a visit to each unique IP address.
IP has the same issues as IPUA, and should only be used when no other options are available.