While Positive Economics looks at trying to establish a theory $($like a cause$-$and$-$effect relationship$)$ based on facts from scientific research Nornat ve Econcrac: looks at:

establishing a principle$-$based on your ownt research and findings.

establishing a principle based on someone else's research

developing a structure of cause$-$and$-$effect relationship based on observation.

establishing a statement based on one's opinion of how things aught to be

Clear my selection