As Stack Overflow grows — or any other Q&A site in the Stack Exchange network, really — there’s a natural pressure to discover and link duplicate questions. The more questions you have, the higher the possibility a given new question isn’t in fact a new question, but a duplicate of an older existing question. Because of this, we’ve continually enhanced the tools for finding, linking, and merging duplicate questions:
One thing I want to be clear about, though, is that duplication is not necessarily bad. Quite the contrary — some duplication is desirable. There’s often benefit to having multiple subtle variants of a question around, as people tend to ask and search using completely different words, and the better our coverage, the better odds people can find the answer they’re looking for. And isn’t that, really, the whole point of this exercise? …