Comparing Google Analytics with Urchin

Many clients use both Google Analytics and Urchin 6. When looking at their web metrics data they often see large discrepancies in visits, visitors and page views - so why is this and what can be done?

First thing to note is that Google Analytics collects information about visits exclusively through a JavaScript page tag. This means that devices that are not JavaScript enabled which visit a website tagged with Google Analytics will not we recorded by Google Analytics. Such devices will include some mobile phones, PDAs and (I understand) some accessibility devices. Also, of course robots from search engines, spammers and prices comparison sites, etc will also not generally be included - because they generally do not understand JavaScript.

Secondly, Google Analytics also sends four (sometimes five) cookies out to the visitor. Again this restricts the ability of Google Analytics to record the previously mentioned devices - becasue they generally do not accept cookies.

Google Analytics' JavaScript page tags can also be affected by corporate firewalls and, of course, by not even being present (missing tags). You could say (and I often do) that poor tagging is Google Analytics' Achilles' heel.

However, Urchin on the other hand is a web access log analyser and so assuming your log is picking up all such devices - Urchin will record that visit. Urchin also is able to work in two ways. It can be configured to work just like Google Analytics - with JavaScript page tags and Cookies to detect visits - more on this later - or in its default configuration of "IP and User Agent".

With IP and User Agent, Urchin counts a visit and visitor when there is an IP address and User Agent entry in the web access log. Common search engine user agents like Googlebot and MSNbot are excluded from the visits report (although they are reported in Urchin > IT reports > Browsers and Robots) , but there are many robots that Urchin does not know about and so this is one area where your visits and visitor numbers will be higher in Urchin than in Google Analytics. One thing to do is apply some filters which try and exlude (on the basis of user agent name) such robots.

The other point to note is that if you are counting visits from robots, they consume much more content than human visits and so your page views will also be inordinately greater in Urchin than in Google Analytics.

Here are some filters for you to add your Urchin profile(which may help):


1)
Filter Name: 1 - Generic robot exclusions - ivantage
Filter Type: Exclude Pattern
Filter Field: cs_useragent (RAW)
Filter Pattern:
analyzer|archiverbandit|bot|catch|catcher|check|checker|copy
|crawl|cruiser|curl|dig|digger|down|download|fake|ferret|fetcher
|fido|fly|forager|get|gobble|grabber|gulper|harvest|hoover|http|
image|incy|Index|Indexer|Info|Inspector|jump|jumper|legs|link
|linke

2)
Filter Name: 7 - Specific common bot exclusions - ivantage
Filter Type: Exclude Pattern
Filter Field: cs_useragent (RAW)
Filter Pattern:
AhoyAhoy|Alkaline|ananzi|Anthill|apache|appie|Arachnophilia|Arale
|Araneo|AraybOt|Aretha|ARIADNE|arks|AskJeeves|ASpider|ATN
|Atomic|Atomz.com|AURESYS|BackRub|Bjaaland|BlackWidow|Blinde
|Bloglines|BlogSearch|Bloodhound|bright.net|Brother|BuzzCore
|CACTVS|Cal

3)
Filter Name: 9 - Specific bot exclusions - ivantage
Filter Type: Exclude Pattern
Filter Field: cs_useragent (RAW)
Filter Pattern:
WildTangent|Kernel|Pheedo|Internal|CFSCHEDULE|Java
|panscient.com|panscient|PubSub|ColdFusion|veoh|SimplePie
|Mediapartners|HTC_TouchDual Mozilla|Vienna|libwww perl
|ia_archiver web.archive.org|porn_viewer|larbin|WebCopier
|MAUI|Cooliris| poo|WebDAV|MiniRedir

Here's how one might look in Urchin












However, if you are using Urchin with the urchin.js, and the utm.gif - in other words, you are using the Urchin Traffic Monitor, then the mechanisms for recording visits are now similar and you would hope that your stats in Google Analytics are the simlar to those of Urchin.


However, there are a few more reasons why this might not be the case:

1) Page view definition model. In Google Analytics, a page view is defined by the urchinTracker(); or the pageTracker._trackPageview();. In Urchin a page view is defined by you in the Pageview Mimes Match in Profile Settings > Reporting.

So, additional page views that Urchin will record are any pages and templates you may not have tagged with Google Analytics such as .php, rss, xml, etc. A nice report to analyse this is in Urchin > IT reports > Pages & Files > File Types

2) Google Analytics's, by default, does not record downloads but Urchin does. So again looking at Urchin > IT reports > Pages & Files > Downloads would reveal other page views that Google Analytics just won't record.

3) Visits that engage exclusively with the above mentioned mime types will also not feature in Google Analytics, but they will in Urchin.