What is the practical difference between 'synthesis of published material' and 'original research' as it relates to Wikipedia's NOR policy?

The practical difference between 'synthesis of published material' and 'original research,' within Wikipedia's No Original Research (NOR) policy, lies in whether a new conclusion or position is being advanced that is not explicitly stated by the sources themselves. 'Synthesis of published material' involves combining information from multiple reliable sources to present a coherent overview of a topic. This is acceptable as long as the synthesis does not create or imply a conclusion that is not directly supported by the sources individually. The editor is essentially summarizing existing knowledge. 'Original research,' on the other hand, involves introducing arguments, ideas, or conclusions that are not explicitly stated in the sources. This includes drawing novel inferences, interpretations, or connections that go beyond what the sources directly say. It is unacceptable because it represents the editor's own analysis or opinion, rather than a summary of existing knowledge. For instance, if Source A states that 'Company X's sales increased by 10%,' and Source B states that 'Company X invested heavily in marketing,' it is acceptable synthesis to say 'Company X increased sales by 10% after investing heavily in marketing,' citing both sources. However, it would be original research to conclude that 'Company X's marketing investment directly caused the 10% sales increase' if neither source explicitly makes that causal claim. The crucial point is that the conclusion must be directly and explicitly supported by the sources; otherwise, it constitutes original research.