I was trying to replicate something similar to Justin Grovers post on content blocking for iOS 9 traffic, but I can't seem to get the normalization option to be in a selectable state (greyed out). Any ideas to what I'm doing wrong?
When you drag and drop the line graph on the freeform panel, click on the gear icon while the graph is still empty and then check the Normalization option. Then go ahead and select the data to be displayed.
I did some more research on the Normalization function and found out it works a little differently in Analytics as compared to the usual way. There are some caveats and workarounds.
Normalization works if it is the same metric and you are comparing different date ranges for the same metric or same metric with different segments applied. You would need to pull "day" as dimension for it to work. (That is you have to trend the report).
Also, there is a glitch. If I get normalization enabled and then add metrics, it will still be enabled. Similarly, if the normalization is disabled due to multiple metrics and then I remove to have only one, it will still be disabled.
Well the normalization option is greyed out because essentially your graph contains the view on one dimension only (occurence) with two different segments. So the scale of the number remains the same. Normalization works when you are comparing numbers being measured in different quantities. For example, if you are displaying Visits and Unique visitors in the same graph you can normalize because those are different dimensions/metrics.
I hope his clears your doubt, let me know if you have further questions. Thanks!