<p>I'll say 3 as well, but there should be a very liberal criteria for determining whether a question has statistical content.  For example, a seemingly purely programing based question (e.g. how to work with and store data in sparse matrices) should not be bounced to SO so long as the question asker specify that it is their ultimate goal to perform a specific statistical procedure on that data. There are many cases where it will be better to ask that type of question to people familiar with the procedure (and the available methods for conducting that procedure) rather than to a general programing forum.  That is, a general programming forum may technically solve a problem but leave a dataset in a state that is not readily amenable to analysis.</p>
