<p>This issue has been litigated many times on meta.CV, and the specific thread referenced is clearly off topic.  The question is <em>only</em> asking about how R works (what package / function, and an error message), not the underlying statistical issues.  In addition, the explicit questions (the places where there is a "?"), are the title, "How to... in R... ?", and the final sentence / paragraph "Any suggestions?" (which is obviously too broad).  The answer is <em>only</em> code and does not contain any statistical explanation, as you note.  </p>

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<p>Let's address some of the specific issues:  </p>

<p><strong>Should CV offer code help and/or tutorials as long as the models discussed are "far from trivial"?</strong>  </p>

<p>No.  This is not training or tech support for any software, including R.  We also don't do tutorials.  Software should make resources available (documentation, books, courses, etc.) to provide adequate assistance to users.  Moreover, "far from trivial" is in the eye of the beholder.  I teach introductory statistics classes, and many of my students would consider a simple logistic regression model to be "far from trivial" (I'm guessing you would not&mdash;at least, I do not).  </p>

<p><strong>Shouldn't we allow such questions here, since there doesn't seem to be a better place to ask elsewhere on the internet?</strong>  </p>

<p>No.  The universe is not required to provide a free, convenient answer somewhere.  And our scope is not determined by the scope of other SE sites, or other sites generally.  Whether or not any suggestion for where a question can be asked can be given, our scope is the same.  To see the illogic in this suggestion, consider applying it elsewhere, say <a href="https://cooking.stackexchange.com/">Seasoned Advice</a>, SE's cooking Q&amp;A site.  Shouldn't you be allowed to ask how to fit a bivariate probit model there, since it isn't on topic elsewhere?  No, because it is outside their scope.  That may not seem fair, since that is a cooking site, and this is a statistics site.  But that's the point, this site is for questions about <em>statistics</em>, not about software (even statistical software) and how to use it.  </p>

<p><strong>Shouldn't we allow this question, since it appears other questions have been allowed?</strong>  </p>

<p>No.  This is a common retort by people who want answers and believe CV should be obliged to give them.  There are several issues: First, the site's standards and scope have evolved over time.  Second, there are many questions asked every day.  No one has read them all.  I don't read all the new questions every day anymore.  If I had seen the thread at issue here when it was asked, I would have closed it immediately.  I have not yet investigated the threads you link, but it is possible they just slipped by and should be closed now.  Third, you need to consider not only the few possible exceptions to the rule, but the many, many threads that have been closed in accordance with our policies.  Moreover, whether or not any other off-topic thread remains open has little bearing on whether this off-topic thread should be closed.  </p>

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<p>I am very sympathetic to the fact that there are people who have questions and need help.  (I have answered over 1.5k questions here, after all.)  I am also sympathetic to the fact that people can find R inscrutable at times and really want help with that&mdash;I've been that person myself more than once.  People commonly say they want to ask here because this is the best site with the highest quality information.  Despite my sympathies, I am also responsible to maintaining the standards of this site, in terms of both boundaries and quality.  In fact, part of the reason the site has high quality information is because we are strict about what we do and how we do it.  </p>

<p>So how do I determine if something is on-topic, or if a seeming code question really "takes statistical expertise to answer"?  It's fairly simple really.  I do not ask if only someone with statistical training would have heard of the test / model at issue, instead, I ask myself what the OP needs explained.  If what needs to be explained is a statistical idea, it's on-topic, if it's not, it's off-topic.  For example, if the question had asked how seemingly unrelated bivariate probit regression works, or how any software could estimate it 'under the hood', that would have been on-topic.  Sometimes people show that what appears to be the same model / test gets different answers from different software.  The issue is always that the software are making different default assumptions or using different estimators.  Other times the way the code is used or how it can go wrong is related to subtle and conceptually difficult aspects of the underlying procedures.  Those are all statistical issues to be explained.  </p>

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<p>In conjunction with my statement that we sometimes miss questions that should be closed, but that their remaining open is not a valid argument that another off-topic question should be allowed, it may be worth laying out the history here.  I became aware of this thread because the answer was flagged for deletion as not an answer by CV's standards.  I agreed with that, but nonetheless I did not delete the answer.  The problem is that the question is clearly off topic and no post that actually answered the question would be a valid CV answer.  On the other hand, I recognize that the answer posted probably does help the OP (and future readers, since the thread won't disappear, even if closed).  So I left the answer, but closed the question.  </p>
