Who are the main reformers of 19th century that attempted to build a methodology around observation of child language learning?

1) Losanov

2) Gouin, F.Franke

3) A.Meillet, C.Bally, S.O.Kartevskii

4) Aristotle, Spinoza, Potebnia

5) L.V.Shcherba, P.V.Bogatyrev, E.D.Polivanov