Julien noticed a discrepancy between the clickthrough rate on the Portal dashboard and the rate reported in the most recent Portal A/B test analysis. The only difference is that the data used in the A/B test report underwent an additional cleaning step wherein duplicated events were removed. Therefore the clickthrough rate that is surfaced on the Portal dashboard is calculated using faulty data that has A LOT of duplicate events (any session should have at most 1 landing event and 1 clickthrough event). An example of faulty data:
|**Session Hash** |**Type of Event** |**Section Used (if any)** |**Timestamp** |**User Agent** |
|003e072635bb8367 |landing |no action |2016-04-18 18:03:18 |"Mozilla/5.0 (Windows NT 10.0; WOW64; rv:45.0) Gecko/20100101 Firefox/45.0" |
|003e072635bb8367 |clickthrough |search |2016-04-18 18:03:24 |"Mozilla/5.0 (Windows NT 10.0; WOW64; rv:45.0) Gecko/20100101 Firefox/45.0" |
|003e072635bb8367 |landing |no action |2016-04-18 18:10:10 |"Mozilla/5.0 (Windows NT 10.0; WOW64; rv:45.0) Gecko/20100101 Firefox/45.0" |
|003e072635bb8367 |landing |no action |2016-04-18 18:14:29 |"Mozilla/5.0 (Windows NT 10.0; WOW64; rv:45.0) Gecko/20100101 Firefox/45.0" |
|003e072635bb8367 |clickthrough |search |2016-04-18 18:14:32 |"Mozilla/5.0 (Windows NT 10.0; WOW64; rv:45.0) Gecko/20100101 Firefox/45.0" |
|003e072635bb8367 |landing |no action |2016-04-18 18:22:50 |"Mozilla/5.0 (Windows NT 10.0; WOW64; rv:45.0) Gecko/20100101 Firefox/45.0" |
|003e072635bb8367 |clickthrough |search |2016-04-18 18:22:56 |"Mozilla/5.0 (Windows NT 10.0; WOW64; rv:45.0) Gecko/20100101 Firefox/45.0" |
|003e072635bb8367 |landing |no action |2016-04-18 18:29:24 |"Mozilla/5.0 (Windows NT 10.0; WOW64; rv:45.0) Gecko/20100101 Firefox/45.0" |
|003e072635bb8367 |landing |no action |2016-04-18 18:41:27 |"Mozilla/5.0 (Windows NT 10.0; WOW64; rv:45.0) Gecko/20100101 Firefox/45.0" |
|003e072635bb8367 |landing |no action |2016-04-18 18:42:48 |"Mozilla/5.0 (Windows NT 10.0; WOW64; rv:45.0) Gecko/20100101 Firefox/45.0" |
|003e072635bb8367 |clickthrough |search |2016-04-18 18:42:51 |"Mozilla/5.0 (Windows NT 10.0; WOW64; rv:45.0) Gecko/20100101 Firefox/45.0" |
|003e072635bb8367 |landing |no action |2016-04-18 18:53:12 |"Mozilla/5.0 (Windows NT 10.0; WOW64; rv:45.0) Gecko/20100101 Firefox/45.0" |
|003e072635bb8367 |clickthrough |search |2016-04-18 18:53:15 |"Mozilla/5.0 (Windows NT 10.0; WOW64; rv:45.0) Gecko/20100101 Firefox/45.0" |
|003e072635bb8367 |landing |no action |2016-04-18 18:57:49 |"Mozilla/5.0 (Windows NT 10.0; WOW64; rv:45.0) Gecko/20100101 Firefox/45.0" |
|003e072635bb8367 |clickthrough |search |2016-04-18 18:57:56 |"Mozilla/5.0 (Windows NT 10.0; WOW64; rv:45.0) Gecko/20100101 Firefox/45.0" |
Here are the top 10 sessions from 2016-04-25 by number of events per session:
```
USE log;
SELECT session, type, COUNT(1) AS n_events FROM (
SELECT event_session_id AS session, event_event_type AS type
FROM WikipediaPortal_14377354
WHERE LEFT(timestamp, 8) = '20160425' AND ((event_cohort IS NULL) OR (event_cohort IN ('null','baseline')))
) AS events
GROUP BY session, type
ORDER BY COUNT(1) DESC
LIMIT 10;
```
| session | type | n_events |
| bffdb37f71390448 | landing | 54 |
| bffdb37f71390448 | clickthrough | 45 |
| af4f8d39d0938791 | clickthrough | 29 |
| 44cec5cdd7158153 | landing | 28 |
| 8b94560060a388ef | clickthrough | 28 |
| 02d93779e11e09b7 | landing | 21 |
| 22d37669555e82be | landing | 19 |
| 8b94560060a388ef | landing | 17 |
| 48f3fc8f0f5c8bb0 | landing | 17 |
| 4558e753c79b0ce4 | clickthrough | 17 |
That is not good and should be corrected in the nearest future.