Question source: [Which questions are the least frequently answered?][1] Note: the results here are only for Stack Overflow, as that is the most difficult to analyze due to data size. All the queries for this one are public, so if you want to run against the other sites, you can do so at your leisure on SEDE. For the purposes of this discussion, when I say "quality answer" I mean an answer that qualifies a question as "answered" (i.e., not-"unanswered"). --- **For a given topic (tag), how unlikely is it to receive a quality answer?** Data source: March 14, 2012 SEDE data: [SEDE query][2] <pre> Tag Questions Unanswered Rank UnansweredPct PctRank android 155514 49813 1 32.0 2 facebook 22584 9029 18 40.0 1 ios 51057 13902 10 27.2 4 iphone 124468 26074 7 21.0 13 web-services 17860 5141 30 28.8 3 asp.net 114440 22832 8 20.0 16 jquery 161533 29186 6 18.1 21 javascript 186792 31103 4 16.7 24 java 219256 32440 3 14.8 30 php 202304 30630 5 15.1 29 wcf 20116 5181 29 25.8 5 c# 277900 35657 2 12.8 38 ajax 34092 8010 20 23.5 10 </pre> - The results were truncated for brevity; the rankings are from 1 (most) to 50 (least); overall, the list is sorted by an arbitrary metric to put the most "problematic" tags at the top of the list. - [tag:Android] is particularly concerning. This was also the case when I did the original analysis, so it doesn't look like things have changed much since then. It may be that the community lacks enough experts to tackle answering the huge volume of questions. It may also be that the APIs are not yet mature and there are lots of people running into problems that *have no solution*. - The results for the bread & butter tags of [tag:C#], [tag:jquery], [tag:javascript], etc., are really positive, with both huge volumes of questions and a very low percentage of unanswered questions. **If the topic is mainstream and well-understood, it is highly likely to receive a quality answer.** While that isn't particularly surprising, it does confirm our intuition. - This analysis did not take into account a question's vote score, but I suspect there is a positive correlation between high quality answers and high quality questions, regardless of topic. --- **For a given subtopic (2-tag combination), how unlikely is it to receive a quality answer?** Data source: February 6, 2012 NDA dump, considering combinations of the top 150 tags This analysis can be run against the public data dumps, but the query is very very heavy. (Read: best of luck running against Stack Overflow.) The SEDE query is [here][3] if you want to run against other sites (you may need to add a minimum threshold for the combinations for the results to be meaningful). <pre> Tag 1 Tag 2 TotalQuestions Unanswered UnansweredPct facebook php 3056 1071 35.1 ios ipad 4821 1490 30.9 listview android 4242 1263 29.8 wordpress php 4203 1218 29.0 ipad objective-c 4077 1126 27.6 ios xcode 5099 1407 27.6 ajax asp.net 3632 990 27.3 android java 17750 4546 25.6 html5 javascript 3937 1003 25.5 ... database mysql 6891 1005 14.6 jquery html 14092 2046 14.5 cocoa-touch iphone 11925 1718 14.4 objective-c cocoa 8138 1131 13.9 css html 26566 3612 13.6 django python 11093 1502 13.5 winforms c# 15504 1979 12.8 c# .net 54198 6591 12.2 c++ c 9994 1199 12.0 sql mysql 14531 1251 8.6 </pre> - The results are ordered by UnansweredPct descending, and the top 50 of those were recorded - People apparently have a hard time with list views in Android. - These results pretty much mirror the single-tag analysis. --- **Which are the most frequent subtopics (2-tag combinations)?** (This is a bit tangential to the main topic, but I thought it was interesting to include.) Data source: February 6, 2012 NDA dump, considering combinations of the top 150 tags As with the previous query, this can run against the public dumps, but you have to limit the number of combinations for the bigger sites. The SEDE query is [here][4]. <pre> Tag 1 Tag 2 Questions jquery javascript 55839 .net c# 54198 objective-c iphone 36700 asp.net c# 35233 mysql php 29666 css html 26566 html javascript 23540 ios iphone 20424 android java 17750 </pre> --- If you'd like to have a look at all statistics I collected for this question, you can download the Excel spreadsheet [here][5]. [1]: https://meta.stackexchange.com/a/89911/136558 [2]: http://data.stackexchange.com/stackoverflow/query/42823/unanswered-questions-by-tag [3]: http://data.stackexchange.com/gaming/query/42824/most-frequently-unanswered-two-tag-combinations [4]: http://data.stackexchange.com/stackoverflow/query/36879/most-frequent-two-tag-combinations [5]: http://jsstatic.net/Content/SECommunityStats/Unanswered%20Questions%20%28Stack%20Overflow%29.xlsx