Archive for February 5th, 2007

Sample size calculator

Statistics can be very confusing and often data is interpreted wrong. Especially when it comes to A/B testing and sample size. Here some of the tools/sites that I like:

Sample Size Calculator via Surveysystem
Java applets for power and sample size via Ruth Lenth

Inference of two Sample proportion by Rebecca Su

Frequency Stats via Swogstat

More tools are in our tools section. Please feel free to add any tools that help your daily work


Interview with Jim Sterne

I didn’t inteview Jim Sterne, but Eric Enge over at did. It is a really interesting interview and besides all the great anwers, I certainly will remember the following statements for my work:

 1. Web analytic data is not precise, but as long as the inaccuracies are consistent, then the delta is true.

2. [The most difficulty for 2007 in webanalytics is] Finding people that can do the job

3. Microsoft has announced that they are going to be releasing something similar [like Google Analytics] in the May timeframe

4. Google Analytics and Microsoft can’t touch the high end tools, such as Omniture, WebSideStory, WebTrends, and Coremetrics.



Take the Google logo off your website!

After spending a few million $ with Google Adwords, using Adsense on several sites with more than XX million impressions a month and after promoting writing about Google Analytics for free, I received an email from Google Germany (!) to remove the Google logo.

Google Germany is at least so friendly and asks me to fax a permission request to the Google US plex. However the Google logo guidelines says:

“That means we have to turn down many requests because sites imply that Google is endorsing them or is otherwise affiliated with them”

I understand their concerns about their brand, but there are about 40,900,000 Google logos out there.