Bug 143552

Summary: The results of A/B testing should state statistical significance
Product: WebKit Reporter: Ryosuke Niwa <rniwa>
Component: WebKit WebsiteAssignee: Ryosuke Niwa <rniwa>
Status: RESOLVED FIXED    
Severity: Normal CC: barraclough, benjamin, cdumez, kling, koivisto
Priority: P2    
Version: 528+ (Nightly build)   
Hardware: Unspecified   
OS: Unspecified   
Bug Depends on:    
Bug Blocks: 141443    
Attachments:
Description Flags
Adds the feature
cdumez: review+
Screenshot 1 (statistically significant)
none
Screenshot 2 (statistically insignificant) none

Description Ryosuke Niwa 2015-04-08 20:42:55 PDT
When A/B testing completes, we should report whether differences are statistically significant or not.
Comment 1 Ryosuke Niwa 2015-04-08 20:59:18 PDT
Created attachment 250410 [details]
Adds the feature
Comment 2 Ryosuke Niwa 2015-04-08 21:05:09 PDT
Created attachment 250411 [details]
Screenshot 1 (statistically significant)
Comment 3 Ryosuke Niwa 2015-04-08 21:05:24 PDT
Created attachment 250412 [details]
Screenshot 2 (statistically insignificant)
Comment 4 Chris Dumez 2015-04-08 21:15:02 PDT
Comment on attachment 250410 [details]
Adds the feature

View in context: https://bugs.webkit.org/attachment.cgi?id=250410&action=review

rs=me

> Websites/perf.webkit.org/public/v2/app.js:1339
> +        for (var i = 0; i < configurations.length; i++) {

Looks like we only need to go up to configurations.length-1 ?

> Websites/perf.webkit.org/public/v2/app.js:1341
> +                var summary1 = configurations[i].summary;

should probably be outside this for loop as it doesn't change.

> Websites/perf.webkit.org/public/v2/app.js:1362
> +            return 'Not statistically significant' + details;

missing space after "significant".

> Websites/perf.webkit.org/public/v2/js/statistics.js:67
> +            return [null, null];

In the regular case you return a dict but here you are returning an array?
Comment 5 Ryosuke Niwa 2015-04-08 21:58:35 PDT
Comment on attachment 250410 [details]
Adds the feature

View in context: https://bugs.webkit.org/attachment.cgi?id=250410&action=review

Thanks for the review & nice bug catches!

>> Websites/perf.webkit.org/public/v2/app.js:1339
>> +        for (var i = 0; i < configurations.length; i++) {
> 
> Looks like we only need to go up to configurations.length-1 ?

Oops, nice catch!

>> Websites/perf.webkit.org/public/v2/app.js:1341
>> +                var summary1 = configurations[i].summary;
> 
> should probably be outside this for loop as it doesn't change.

Fixed.

>> Websites/perf.webkit.org/public/v2/app.js:1362
>> +            return 'Not statistically significant' + details;
> 
> missing space after "significant".

Oh, there is a leading space in "details".

>> Websites/perf.webkit.org/public/v2/js/statistics.js:67
>> +            return [null, null];
> 
> In the regular case you return a dict but here you are returning an array?

Oops, fixed.
Comment 6 Ryosuke Niwa 2015-04-08 21:59:12 PDT
Committed r182587: <http://trac.webkit.org/changeset/182587>