We're very used to having to explain what the difference is between total and unique events in Google Analytics. Like many other puzzling metrics, this has consistently been a head-scratcher for more people than we can count.
Whilst you may have been in this situation like we have, you might not know that this was often due to a problem in the metric! But thanks to the released update, this is now fixed for both internal and clients’ reporting. You can read more about this update in Google's blog post: Improving Google Analytics Events with Unique Events.
So what was the issue?
The issue was that the unique events metric wasn’t correctly taking into account all event dimensions when calculating your numbers for the reporting. This caused many discrepancies, which probably created those numerous confusing situations around what the number stood for.
The unique events metric was always meant to show you the unique count of individual interactions (or events) within a single session. So if someone downloads the same PDF 3 times during 1 session, then that counts as 1 unique event.
Instead, it has been counting how many unique numbers of times a specific combination of values is seen in the report per each row.
This example by Google is very helpful in getting to grips with what this means.
In the example at the top where you can see all three values for various event fields, you get the same count for both new and old unique events metric - each gets 3.
In the second example, we exclude one dimension and get a different result. Now, because one set of values is hidden (event label) then the calculation takes into account only what is seen in the report. But the new metric, accurately now, knows that there is a third set of data, which is taken into account in its calculation.
What’s the fix?
Current unique events metric has been renamed to ‘Unique Dimension Combinations’ (UDC) - a bit of a mouthful - to reflect that it was counting the uniques of dimension combinations, not individual interactions! You’ll still be able to use it as a metric if you need to compare old versus new data or are doing any analysis on the legacy data that it is attached to.
The calculation for the unique events metric will now take into account all event dimensions when calculating the number. Due to this change, all event fields are now also required to contain a value - any blanks will get a (not set) value.
In your standard Google Analytics reports, you’ll see the new unique events metric with the label ‘NEW’ attached to it. That’s when you know you’ve got the fixed metric in your reports.
The new unique events metric will apply to the data as far back as May 2016.
BUT, the fix won’t be applied automatically to your custom reports. If you have any custom reports that reference the old unique events metric, the naming will be updated to UDC.
Google has provided a neat method to update your custom reports too. So you get a choice whether you want to keep using the deprecated old metric or switch to the updated unique events metric. When making the choice, bear in mind that UDC may eventually be removed so you might want to jump on the fixed uniques metric straight away.
Whilst not the most exciting update on its own, this is important for the accuracy of reporting. All of our clients use events tracking so any updates to improving the accuracy of events reporting and analysis are a welcome change.
Have any questions about this update? Get in touch with one of our experts!
- What is Google Analytics? Overview for beginners
- Common reasons for tracking events
- How to set up event tracking in Google Tag Manager
Images: courtesy of Google