Experience or observations are things or events that are sensed, either directly by a human body or with the aid of mechanical sensory devices, such as telescopes or microscopes, or eyeglasses or hearing aids. It is normally the best source of knowledge available to a human being. Unfortunately in the English language, reason also often means the much less truthful and more error prone process of deductive thinking, as well as other methods of guessing. Intuition or insight is the direct perception of reality without the use of the senses. I suspect, and this is only a suspicion at this point, that the scientific explanation of intuition is that the brain is detecting quantum fluctuations in the fabric of spacetime itself.
Human senses are capable of detection at the quantum level obviously since photons are quanta.
Free will would otherwise be prohibited in a universe where causality is true. There is nothing supernatural or mystical occurring. This is not to be confused with the more usual use of the word intuition to mean psychological subconscious reasoning, which is a different matter altogether being the probable foundation of guessing, which is where it lies in truth-value. Metaphysics or ontology is the study of the nature of reality. Metaphysics, epistemology, and semantics are tightly interwoven.