Scientists need to carefully look at their specimens in order for them to create several observations. These observations can yield to possible questions that they need to answer.
When they have numerous questions to be answered, they can formally create several hypothesis and arguments to directly answer questions or creates theories and postulations on the matter/s that they want to answer.
A scientific inquiry always begins with good observation and is the foundation of any scientific argument or research. The same goes for other fields of Physics, Chemistry, Math, among others.