According to the scientific method, why does a physicist make observations and collect data?

The scientific question is a way of understanding why things behave the way they do. In this case, a physicist (scientific method is also applied in other fields), needs to make observations, to set a goal and make the suitable research question.

Collecting data is important, because it will allow to predict behaviors, trends or patrons, which will be of great use when generating an hypothesis. Which according to the scientific method, is what comes after the the previous observations.