I am not an expert in epistemology and I am currently searching for the name of a particular approach in physics (an historical one). Since Galileo, the role of the physicist is to simplify the physical systems (ie do not consider the temperature of a room, or the wind speed as relevant parameters to study the behaviour of a pendulum) in order to deduce the fundamental laws of Nature. In this approach, the observed phenomenon are seen as coming from simple but fundamental laws. And it works well.
But another historical approach was to try to explain things without fundamental laws, but only based on reproductibility and experience : in this approach the dynamic of a pendulum is not seen as a consequence of gravity and laws of motion but as an independent phenomenon. This approach is an approach of "models without laws". It was the traditional approach for very complex systems, like in medicine : for this "input", the experience tell me that I have this "output" (but I am not even searching for the underlying fundamental laws).
In a certain sense the first approach thinks in terms of laws, cause and consequences, and the second one thinks in terms of models and correlations.
So my question is : what are the correct terms of these approaches in epistemology ?