>>33415
Investigation differs from experience in the sense that one voluntarily researches about a subject, the one who is learning goes out of his way to learn about something. Observation and experience are not necessarily something the subject wanted to go through voluntarily, many things can be learned from seeing people behave, but that knowledge isn't something that the user was actively searching for. Experience is the most basic one, you mess something up, you feel the consequences, so you need to see what you did wrong to avoid it. Can be related to observation but with more primal activities (ie: not touching hot stuff) it becomes something so basic a dog can recognize it.
Though the idea of these kinds of learning processes is something my mother told me and she's quite retarded in some areas, so I should probably take this with a pinch of salt.