Monthly trend comparison using tables in Google Data Studio

Question

I'm quite new to GDS and I've been experimenting with the comparison date range to see the increase in % between current and previous month

I've managed to get a slight result but it's not showing the correct % increase which I have manually calculated to confirm.

The values are

No of Reviews (calculation)

July - 379 reviews / 314 positive reviews = 82.85%

August - 480 reviews / 458 positive reviews = 95.42%

Manually Calculated Difference = 12.57%

GDS Comparison Difference = 15.2%

The date column itself is formatted as "YYYYMMDD" and I've tried the comparison and calculation field options on the metric but to no avail

It feels like I am getting a comparative % rather than a direct increase

Any help/guidance would be greatly appreciated as I have tried the GDS forum several times but there is very little activity on there

Thanks so much

Dan

Answer 1

On the style on your table, under show compare, check Show Absolute Change to get the exact difference.

Answer 2

It's not ideal but to do this in GDS you need to create a new column in Google Sheets which is literally the values you need from the previous month. I.e.

date      |reviews|pos reviews|prev month reviews|prev month pos reviews|
2019-08-01|480    |458        |379               |     314              |

You can then create 2 calculated fields for this month % positive and last month % positive and a 3rd for the difference.

There are other wyas you can try to do this but they get a bit messy and manual so that's probably a good starting point. GDS is great in some ways (cost being one!) but a little limited in others!