Average Time on Site and Page Views/Visit Data Discrepancy

[cparthasarathy]

Hi Adobe Analytics Experts 

There are around 90 pages and when we average the time on sheet for Avg Time on Site or Page Views/Visit it does not match
 The Average time on site  doesnt tally when we export it and average it , same with Page views/visit
Any insight into it would be very helpful,

Thanks

[yuhuisg]

Are you calculating an average of an average? For example, for Page Views / Visit, are you calculating (4.60 + 3.23 + 2.19 + ...) / (count of rows in the freeform table) ?

If so, then that's a wrong calculation methodology. You can't just calculate an average of an average like that.

So for Page Views / Visits, the aggregate 6.20 that is reported is (sum of Page Views ) / (sum of Visits). A similar calculation is done for the aggregate for the Average Time on Site metric.

[cparthasarathy]

Thanks Yuhuisg.

Would that means the  average time on site and pages per visit are computed row wise by the dimension and should not be averaged or summarized column wise.

[yuhuisg · Accepted solution]

That is correct.

A simple example is the average speed of a car. Let's say a car travels the following:

• 100km in 2 hours
• 60km in 3 hours
• 200km in 2.5 hours

The average speed per segment is:

• 100km / 2 hours = 50km/h
• 60km / 3 hours = 20km/h
• 200km / 2.5 hours = 80km/h

And the average speed for the entire journey is:

(100km + 60km + 200km) / (2 hours + 3 hours + 2.5 hours) = 360km / 7.5 hours = 48km/h

Notice that the average speed for the entire journey is NOT (50km/h + 20km/h + 80km/h) / 3 = 50km/h, because that is just wrong maths.