After posing a hypothesis, the first step in linguistic research is to collect language data. This is easy if you can restrict yourself to your native language but this is often not enough. After all, linguistics not just about one language but about Language in general and thus about cross-linguistic patterns. Those patterns become only clearer if they can be discriminated within several languages.
Once data are collected by someone they are often included in some database so they can be used by other researchers as well. Those databases often aim to provide material for a certain linguistic phenomenon either on a syntactic, morphologic or some other level. For example, at UiL OTS at the Art Faculty of the Utrecht University, there is a database about anaphora and their strategies on the syntactic level.