Sampling 102: Controlling Sampling Size in Google Analytics

Tony Villanova - January 31, 2014

In a previous post, we talked about the use of report sampling in Google Analytics.  In this post, we’ll tell you how you can control sampling in order to get a more accurate picture of your site traffic.

In our first post on this subject, we talked about some situations in which you are likely to see sampling within Google Analytics. Most often, this occurs when you’ve requested a report in which there are over 500,000 visits to report. In order to speed the processing of your report, GA will base its report data on a sample size of your total visits. When this occurs, you will see a notice at the top of your report that says, this report is based on X visits:Sometimes, though, you will want to get a more accurate picture of your data. To do this, you will have to run reports based on a larger sample size. Simply follow the steps below to increase the report sampling size in Google Analytics.

Step 1: Locate the sampling icon, which is located in the upper right hand corner of the Google Analytics Interface.Step 2: Once clicked, the sampling slider should display. Move the slider farther to the right in order to increase the accuracy (and sampling size) of your reportFor faster processing, of course, you can move the slider to the left. This means that you will have the highest sampled level which will include the lowest number of visits/sessions used in the calculation.

As soon as you have moved the slider to your preference, your report will automatically update and your preference will be saved for any other sampled reports you view within Google Analytics until you close your session.