<p>We appear to have a number of overlapping threads on imbalanced data. Here are just a few of the more highly-upvoted ones:</p>
<p><a href="https://stats.stackexchange.com/questions/357466/are-unbalanced-datasets-problematic-and-how-does-oversampling-purport-to-he">Are unbalanced datasets problematic, and (how) does oversampling (purport to) help?</a></p>
<p><a href="https://stats.stackexchange.com/questions/283170/when-is-unbalanced-data-really-a-problem-in-machine-learning">When is unbalanced data really a problem in Machine Learning?</a></p>
<p><a href="https://stats.stackexchange.com/questions/6067/does-an-unbalanced-sample-matter-when-doing-logistic-regression">Does an unbalanced sample matter when doing logistic regression?</a></p>
<p><a href="https://stats.stackexchange.com/questions/247871/what-is-the-root-cause-of-the-class-imbalance-problem">What is the root cause of the class imbalance problem?</a></p>
<p>Some of these threads themselves link to and summarise even more questions and answers on the topic (there are 950 questions tagged <a href="https://stats.stackexchange.com/questions/tagged/unbalanced-classes" class="post-tag" title="show questions tagged &#39;unbalanced-classes&#39;" rel="tag">unbalanced-classes</a>, many of them popular). <a href="https://stats.stackexchange.com/questions/357466/are-unbalanced-datasets-problematic-and-how-does-oversampling-purport-to-he">Stephan Kolassa's heroic effort to summarise and pin down the problem</a> is probably the most comprehensive <em>question</em> on the topic, but there are useful answers strewn across many of these threads.</p>
<p>We still keep getting new questions about this, though, and IMO they often seem to attract misleading/incorrect answers. It would be useful to have a canonical thread to point people to on this, but I don't know enough about the topic to judge which of these could be merged/closed as duplicates/deemed canonical, so I thought I'd ask here. <strong>How can we best simplify this situation?</strong></p>
