<p>Methodological questions concerning crowdsourcing and machine learning are on-topic on Cross Validated SE, but they can't be: </p>

<ul>
<li>duplicate</li>
<li>unclear. </li>
<li>too broad.</li>
<li>primarily opinion-based.   </li>
</ul>

<p>Questions which ask for references are not off-topic, but depending on how it is asked some users can consider it 'too broad'. So, always try to be the most specific as possible about the request. </p>

<p>The following CV meta post has additional hints: 
<a href="https://stats.meta.stackexchange.com/questions/2428/question-about-recommended-readings/2429#2429">Question about recommended readings</a>.</p>
