Thought I'd step in here. People who know the mechanics of the relevant logging are as follows:
Android: Dmitry Brant
Desktop: Bahodir (Baha) Mansurov
Mobile Web: Sam Smith & Baha
CC'ing them.
As I understand, Dan Garry's been talking with Baha already on the desktop piece.
It looks like on Chrome/42 UAs the clickthrough rate for a given suggest search form interaction is about 40%. [1]
A couple of patches are pending (JS for emitting event on new EL schema) that will make it possible to figure out how often form submission within a form interaction (ENTER/RETURN, tapping the magnifying class) occurs as well.
Total form interactions (keys on userSessionToken...maybe a better name could be used) minus clickthroughs (click-result) minus form submission (submit-form in the pending patches on the new EL schema) would be a rough proxy of abandonment, I think.
I had heard sendBeacon capable UAs were likely to have greater success emitting the click-result (i.e., when user clicks on a suggestion from the form on the search panel on desktop) event via mw.track, so it may make sense to confine queries for such analysis on desktop to known sendBeacon browsers [2] to increase the odds of high fidelity data just in case there are outlier browsers that manage to somehow emit click-result events through means other than sendBeacon (it seems there may be some of these, assuming non-forged UAs).
-Adam
[1]
> SELECT count(*) FROM Search_11670541 WHERE timestamp >= '20150526' AND timestamp < '20150527' AND event_action = 'click-result' AND wiki = 'enwiki' and userAgent LIKE '%Chrome/42%';
+----------+
| count(*) |
+----------+
| 112 |
+----------+
1 row in set (2.96 sec)
> SELECT count(DISTINCT event_userSessionToken) FROM Search_11670541 WHERE timestamp >= '20150526' AND timestamp < '20150527' AND event_action = 'click-result' AND wiki = 'enwiki' and userAgent LIKE '%Chrome/42%';
+----------------------------------------+
| count(DISTINCT event_userSessionToken) |
+----------------------------------------+
| 112 |
+----------------------------------------+
1 row in set (38.06 sec)
> SELECT count(DISTINCT event_userSessionToken) FROM Search_11670541 WHERE timestamp > '20150526' AND timestamp < '20150527' AND wiki = 'enwiki' and userAgent LIKE '%Chrome/42%';
+----------------------------------------+
| count(DISTINCT event_userSessionToken) |
+----------------------------------------+
| 286 |
+----------------------------------------+
1 row in set (7.26 sec)