==Synthesis of published material serving to advance a position== 
 The following is taken directly from WP:NOR  this is one of the policies that is frequently violated in this article. 

 Editors often make the mistake of thinking that if A is published by a reliable source, and B is published by a reliable source, then A and B can be joined together in an article in order to advance position C. However, this would be an example of a new synthesis of published material serving to advance a position, and as such it would constitute original research. "A and B, therefore C" is acceptable only if a reliable source has published this argument in relation to the topic of the article.  

 An example from a Wikipedia article (note that the article is about Jones, not about plagiarism in general): 

 Smith says that Jones committed plagiarism in Jones's Flower-Arranging: The Real Story by copying references from another book. Jones denies this, saying he is guilty only of good scholarly practice because he gave citations for the references he had learned about in the other book. 

 So far, so good. Now comes the new synthesis of published material: 

 If Jones's claim that he always consulted the original sources is false, this would be contrary to the practice recommended in the Chicago Manual of Style as well as Harvard's student writing manual, both of which require citation of the source actually consulted. Neither manual calls violations of this rule on citing original sources "plagiarism." Instead, plagiarism is defined as using a source's information, ideas, words, or structure without citing them. 

 This entire paragraph is original research, because it is the editor's own synthesis of published material serving to advance his definition and opinion of plagiarism and whether Jones committed it. The editor is citing good sources about best practice (Chicago Manual of Style and Harvard's student writing manual). In an article about plagiarism, some of the points he makes might be acceptable, so long as he provided links or citations to the sources. 

 But in an article about Jones, the paragraph is putting forward the editor's opinion that, given a certain definition of plagiarism, Jones did not commit it. Regardless of the fact that his opinion appears to be supported, other things being equal, by the Chicago Manual of Style, it remains the editor's opinion. 

 For this paragraph to be acceptable in the article about Jones, the editor would have to find a reliable source who had commented on the Smith and Jones dispute and who had himself made the point that: "If Jones's claim that he always consulted the original sources is false, this would be contrary to the practice recommended in the Chicago Manual of Style..." and so on. That is, that precise argument, or combination of material, must have been published by a reliable source in the context of the topic the article is about.