Hands-on Tutorials
How to Measure User Interactions in Google Analytics
Reporting with unique dimension combinations to drive product growth.
This article will take you through the following:
- What is an interaction?
- What’s the difference between event metrics in GA?
- When should you use Unique Dimension Combinations?
- How to calculate Interaction Rate.
What is an interaction?
An interaction is any touch point with an element on a website. These are defined by Analysts or Google Analytics Users and can be clicks, hovers, scrolls etc.
Interaction rate is the percentage of people that interact (click, hover, tap) with an element.
Interaction rate is a very useful measure in the Product Analytics world and helps analysts find areas on websites or apps where the customer may be having trouble.
Let’s say that a Software Engineer notifies us that some of the Add to Cart buttons on the website stopped working and we need to know what percentage of sessions usually use this element so that the development team can understand how urgent getting this button fixed is.
This metric can also be used to offer insight on why a user may or may not convert and can be used as a key performance indicator for goals and objectives.
Need to know information
There are 3 main metrics captured in Google Analytics (Universal): total events, unique events, and a trickier metric to get your head around, unique dimension combinations.
These metrics are commonly analysed using 3 dimensions: Event Category, Event Action and Event Label.
If you are not familiar with Google Analytics (Universal) take a look at my video series to get started:
What’s the difference between the event metrics?
To understand what users are doing on websites and apps we can look to the three event metrics: total events, unique events, and unique dimension combinations, but what’s the difference?
Let’s take a look at an example with data from a sock website. We’ll be looking at interactions with a product component.
If a user clicks on the Add to cart button 4 times, the event will be sent or ‘Fired’ 4 times to Google Analytics and the Total Events metric will be 4.
If another user also clicked on the Add to cart button 4 times, the Total events for this button would be 8. Google Analytics increments the Total Events metric by the number of times the tracking combination has fired.
Tracking combination:
Event Category: Product Card
Event Action: Click
Event Label: Add to cart
For unique interactions, Google Analytics counts 1 for the first time the event is fired in the session with these dimension values and ignores any additional events with the same values.
So in the case of our Add to Cart button, Unique Events would be 2, one for each customer that clicked within a session. The Total Events metric counts each time the value is sent.
Next we have Unique Dimension Combinations. This metric counts the number of unique dimension-value combinations for each dimension in a report. This metric will often be close to the value of Unique Events in most cases but can differ depending on the dimensions you use.
Unique Dimension Combinations allow you to combine or group dimensions without needing to update or add additional tracking.
Example One
This example contains data from the Google Analytics demo account so you can follow along.
Here we have some events from the Google Merchandise Store for the interactions. For the Black Youtube Cap we can see that this product has been quick viewed a total of 1,045 times.
But only 121 of these interactions have been unique.
Here we can see that Unique Events, Sessions and Unique Dimension Combinations are the same. This is because the Category, Action and Label dimensions are sent to Google Analytics at the same time.
Let’s say your stakeholder wants to run a promotion and would like to understand how many people per Device from the United States interacted with Products in general.
If you built a report that contained Country, Device and filtered for Event Category = Enhanced Ecommerce, you would see that unlike before you have different values for the unique metrics. This is because the Country and Device events are sent to Google Analytics at a different time within the session to when the Enhanced Ecommerce event occurred.
Taking unique events in this case would over inflate the audience size for your stakeholders promotion. Unique Dimension Combinations looks at the unique number of Sessions that have triggered these events within 1 session. This gives us the total number of people that had this group of actions.
Example Two
If you went on the Google Merchandise website and clicked on a black hat on the home page, a red hat on the home page, a black hat on the mens page and a yellow hat on the women’s page, your interactions in Google Analytics would look something like the table below.
Total unique events would be 4 and Unique dimension combinations would be 4 for the 4 unique actions you have taken.
If you removed the event label from the report, Google Analytics now shows 2 Unique Events and 1 Unique Dimension Combination for the interactions we had with the Quick view element on the home page.
This is because Unique Events is summing the value of the two interactions that we had with the black and red hat on this page.
Remember that event category, action and label fire to Google Analytics at the same time. In the case of our quick view interactions, we click on the black cap, the interaction is sent to google analytics. Then we click on the red cap and the interaction is sent to google analytics in another event. (Diagram below)
If we want to understand unique interactions for the quick view element overall, we need to combine or group these interactions at the Action category on a unique level.
Example with multiple users
In a case where we have multiple users, User one clicks on the quick view for the black cap, the event is sent to google analytics. User one then takes a quick look at the red cap, this interaction is sent in a separate event to google analytics.
User Two comes along and has a quick look at the black, red and yellow caps. These events will be sent separately to google analytics.
To understand the overall quick view performance we need to combine or group these metrics at event-action level.
If we looked at this in a table, Unique events would show 5.
- 2 for User One
- 3 for User Two
This is because Unique Events is still looking at the data at the beginning of the diagram and is counting User Two’s events as 3 unique hits and User One as 2 unique hits.
Unique Dimension Combinations looks at the combined level of the diagram so it counts 2.
Going back to our stakeholders question — how many people interact with Products in General by device, Unique Dimension Combinations discounts any customers that have clicked on multiple products and counts them once.
When should you use Unique Dimension Combinations?
Understanding how events fire on your website will help you with figuring out which metric to use.
- If the events are sent to Google Analytics at the same time, Unique Events will match with Unique Dimension Combinations metric.
- If the events are sent to Google analytics at different times within the session, these metrics will not match and Unique Events will be inflated.
- If in doubt, always use Unique Dimension Combinations, as this should be correct in both circumstances.
Calculating Interaction Rate
If we wanted to understand how many people interact with the Add to Cart button we would first take a look at all of the sessions who have seen the page where the element lives. In Google Analytics you can create a segment for the page where the interaction takes place to find the number of sessions.
Next we will find out how many Unique Dimension Combinations there are for the event category, action and label for the event that fires for Add to Cart on the Sock product page.
Create a custom report with Page, Event Category, Event Action, Event Label by Unique Dimension Combinations to find this number.
In this example, 100 sessions saw the Sock product page and 80 Unique Dimension Combinations were sent to GA for the interaction of Click Add to Cart.
Now we can divide unique dimension combinations by Sessions * 100 to calculate interaction rate. The answer for our example would be 80%.
Another useful measure is the average number of times an element is interacted with, within a session. (Avg Clicks) This is used to understand pain points.
If an element that should only be clicked once or twice has a high number of avg. clicks this can be an indication of either the user becoming stuck or clicking out of frustration.
Let’s Recap
What is interaction?
- The analysis of behavioural events captured using tags on a website.
Where can I find events in Google Analytics
- In a custom report or stored under Behaviour > Events in the interface.
Main metrics
- Total Events
- Unique Events
- Unique Dimension Combinations
What are Unique Dimension Combinations and when should I use them?
- The unique number of sessions that have interacted with a combination of events.
- Best practice — use all the time when measuring unique interaction.
Happy analyzing!
Chloe 👩🏽💻📈
Twitter: @the_numerist
Github: chloeanalyst
