I don’t know of a solution off the top of my head. I’d recommend you check with Justin Cutroni at Epik One/Analytics Talk. He’s very much the expert on the technical pieces of it.

He’s also on Twitter, @justincutroni.

-Alex

1.) In my experience, I don’t recommend you mix both codes. It generally seems to wreak havoc with a number of metrics, though I’ve never checked the ones you mentioned.

2.) I know that neither code uses a parameter to track recency or frequency. They use a cookie. Now, I’m not sure if changing Google Analytics codes resets the cookie. Since it’s calling a new javascript file, that’s very possible.

I wager that you’re right. First, make sure the codes were both in the same location, which should be before the close body tag,

After that, make sure that any customization you did with urchin is adequately carried over with ga.js. It’s not always the same.

Hope that’s a bit of Google Analytics help.

-Alex

Very nice post. Talking about the first issue “#1 – Mixing urchin.js and ga.js code” I have a couple of questions:

1) Have you ever noticed that moving from urchin.js to a mix between both codes, or going from one mixed environment to just using ga.js, alters your count of “Absolute Unique Visitors”, “Visits” or “New Visitors”?

2) Does urchin.js and ga.js use a different cookie or parameter to track recency or frequency?

I have a case where “it seems” that switching from urchin.js to ga.js had an impact in the count of visitors and visits. What do you think?

Thanks!

Glad I could be of assistance. Yeah, I didn’t know of those Google Website Optimizer & Google Analytics issues either. Then, I was working with a client to diagnose their implementation and we eliminated every other issue I found and that was the one last thing stopping the data.

Good luck with the testing. Where are you sourcing your ideas? Any lessons learned from previous test? I’m becoming obsessed with optimization… :-P

Cheers,
-Alex