Difference in difference is a statistical technique used in observational studies. It can provide insight – but don't be fooled by numbers and p-values into believing it is necessarily true. My ...

This is an archived article and the information in the article may be outdated. Please look at the time stamp on the story to see when it was last updated. For decades now, the storied smog in ...

Google today launched the Knowledge Graph, a new search engine feature that helps users quickly find relevant information using semantic search technology. Now, when a user conducts a search, Google ...