They are:
* Baconian (or Inductive) Experimentation.
This type of experimentation is typified by the phrase, "I wonder want would happen if … ?"
All investigations, Medawar suggests, begin this way.
* Galilean (or Critical) Experimentation.
This is the type of experiment where "actions are carried out to test a hypothesis or preconceived opinion by examining the logical consequences of holding it." Here Medawar's words reflect the ideas of Sir Karl Popper (1902-1994).
* Aristotelian (or Demonstrative) Experimentation.
This type of experiment is "intended to illustrate a preconceived truth and convince people of its validity."
and then there is...
* Kantian (or Deductive) Experimentation.
This type of experimentation is based on: "Let's see what happens if we take different view" and consists of "experiments in which we examine the consequences of varying [our] axioms or presuppositions."
Taking a different view is not just useful or important when it comes to scientific experiements. It makes a big difference when just looking at the world.
Here are some images to make one think (differently):
and what about this...?