Google Analytics Session Quality | Understand | Use | Decode

Google Analytics continues to find ways to make it easy for users without marketing or analytics experience to understand data and help them automate marketing campaigns. As part of this exercise Google Analytics recently launched Session quality (Beta) metric, this metric helps users in understanding quality of the traffic without diving deep into data and also enables them to use build user cohorts for remarketing campaigns.

In this article we are going to understand how this metric can be used and also we will try to decode the formula of this metric.



Session quality as metric defines user’s proximity to conversion(ecommerce transaction) with 100 being highest proximity and 1 being lowest, while 0 representing sessions where session quality is not calculated.

How to find session quality report?

Session quality report can be found by navigating to Audience >> Behaviour >> Session Quality. First part of the report shows a histogram for number of sessions against session quality / session quality bucket with session quality of 100 being highest quality and 1 being lowest quality.

1st part

Second part of the report show avg session quality as metric against acquisition channels along with other behavioural metrics like Sessions, Bounce rate, Transactions etc.

2nd Part

Insights from session quality report

Gaining insights from sessions quality is pretty straight forward as the 1st image shows this report shows distribution  of  number sessions against  session quality. In some cases where GA has defined session quality in buckets like 2-5, the bucket can be easily expanded or collapsed to get sessions at individual session quality or at bucket level. Apart from only session quality this report also shows sessions with and without transactions. The higher the session quality higher sessions with transactions will be as per definition of the metric.

This metric can helps in understanding which source / medium / campaign / content / keyword is / are driving you highest / lowest quality traffic. With this insight marketing budgets can be planned in more efficient manner with highest session quality sources getting large part of budgets. This can also help you in managing bids of your keywords and bucket them in high / low quality keywords / placements.

Using the same metric remarketing audiences can also be built and used as audiences list in Google AdWords as shown in video below.

How is session quality calculated?

Although Google has not officially announced the formula used to calculate session quality (hope they do). I tried to run some experiments to at least understand which metrics are being used in to calculate session quality. To me obvious suspects where bounce rate, pages / session and Agv. Session duration.

From this short list i discarded Avg Session Duration as it’s practically output of pages / session so both will yield same results. Now left with only 2 metrics Pages  / Session and bounce rate I created 2 custom reports

Custom report 1

Source / Medium | Bounce rate | Pages / Session | Avg Session quality

Custom report 2

Date | Bounce rate | Pages / Session | Avg Session quality

Based on these reports the correlation coefficient between pages / session and Avg Session quality was respectively 0.8 and 0.7 for these reports. Although this suggests that pages / session is one of the metrics used to calculate session quality, correlation coefficient between bounce rate and Avg. Session quality was -0.2 for both reports indicating that bounce rate is probably not one of the metrics used to calculate session quality or has very low weightage in the calculation.

I will keep testing correlation with some other metrics and Session quality if you have any ideas please comment and I will post results on your ideas.

Possible Pitfalls : While Session Quality is a very useful metric and saves heaps of time required for data mining to find quality sources, at the same time its important to keep in mind that highest quality sources by design are limited and have limitations on scale. This metric will helps in balancing quality of sessions and its quite impossible to have all sessions of highest quality.

Wishlist : One of my favorite features of Google Analytics is weighted sort, which lets me sort by quality metric like bounce rate by adjusting the sorting based on quantity of sessions to have more relevant sorting. Currently weighted sort is only available to metrics represented by as % value, but if Google can extend the same support to quality metrics like session quality it will make even more easy to use and act on.


 Official Documentation on Google Analytics Session Quality 

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AuthorNIkhil Parachure

Nikhil is nothing short of "Swiss Knife of Digital Marketing" over the course of last 10 years he has been involved in practically every facet of Digital Marketing and Analytics. Starting career with paid search Nikhil has built and managed award winning digital campaigns, has been Google Adwords Top Contributor, Planned and implemented several complex and large scale web and mobile analytics implementations. Currently working for a leading ecommerce platform in India as Head of Digital Marketing Nikhil has also conducted analytics and marketing trainings for several MNCs.

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