<p>Q&amp;A sites like Cross-Validated  are not aggregators of information available over the web. They exist because general sources like Wikipedia do not suffice, and they are supposed to offer expertise focused on their field. Obviously what we write in this forum is not parthenogenesis, but neither is just aggregation : it is a purposeful <em>synthesis</em> of sources (our own brains included), guided by the question at hand. In this case the "question" is the name of the tag, and we should approach the content of the tag wikis and excerpts in the same spirit as when answering a question -and even more so, since tag content requires an even more distilled and concrete knowledge of the subject. In the answers we do mention and point to external references - but how often do we copy/paste passages from them?</p>
