Comment by knightoffaith

Broadly speaking, philosophers of science don't think there's a generic answer to what differentiates scientific inquiry from not-scientific (or pseudoscientific) inquiry. Popper put forward the criterion of falsifiability (if it's falsifiable, it's science, otherwise, it's not science), but after Kuhn and Feyerabend's arguments, philosophers generally drifted away from thinking there's some hard-and-fast rule to differentiate science and pseudoscience.

If you're interested in these issues, you might enjoy Chalmers' What is this Thing Called Science?, an introduction to the philosophy of science that addresses issues like these. Or a primary source like Feyerabend's Against Method, quite a fun read, though maybe not one that many philosophers of science today would give their full-throated endorsement of.