Hello. This is the first time I am reporting a "suspected" bug, apologies if the description is rather unorthodox.
I have been calculating metrics for the project Let's Fill the Gender Gap that took place in Geneva in 2015 and 2016 and I have received several strange results on a variety of attempts at running reports with different cohorts in Wikimetrics.
For instance, here are the results I came across when calculating the 90 day retention rate for active rolling editors for the following cohorts ( 5 edits) :
Letsfillthegendergap_session1 ( As from 15th December 2015)
->I obtained the figure of 22 out of 27 participants - very high
Letsfillthegendergap_session2 ( As from the 12th of April 2016)
->I obtained the figure of 0 when I know that a minimum of 3 active contributors should appear in the results - very low
Letsfillthegendergap_sessionHESSO ( As from the 24th May 2016)
I obtained the figure of 12 out of 13 - very high
Letsfillthegendergap_group4_V2 ( As of the 28th June 2016)
I obtained the figure of 19 out of 21 - very high
When changing the number of monthly edits to try to figure out a trend the exact same figures come out from 5 to 15 to 25 monthly edits which indicates that there is probably an underlying issue.
I use google chrome as a web browser - I have no idea if this might have an incidence.
I had to calculate many metrics for those workshops and I am know quite unsure of the validity of the results I obtained. I would much appreciate any help to check if the 4 enquiries above have experienced any issues and to have any advice on how to be sure my previously collected results are correct. Many thanks for your help.