Philosopher of chemistry Jaap Brakel defines protoscience as "the study of normative criteria for the use of experimental technology in science."
On protoscience Thomas Kuhn said that they "generate testable conclusions but ... nevertheless resemble philosophy and the arts rather than the established sciences in their developmental patterns. I think, for example, of fields like chemistry and electricity before the mid-eighteenth century, of the study of heredity and phylogeny before the mid-nineteenth, or of many of the social sciences today." While noting that they meet the demarcation criteria of falsifiability from Popper, he questions whether the discussion in protoscience fields "result[s] in clear-cut progress". Kuhn concluded that protoscience, "like the arts and philosophy, lack some element which, in the mature sciences, permits the more obvious forms of progress. It is not, however, anything that a methodological prescription can provide. ... I claim no therapy to assist the transformation of a proto-science to a science, nor do I suppose anything of this sort is to be had".
^Kuhn, Thomas (1970). Imre Lakatos and Alan Musgrave, ed. Criticism and the growth of knowledge, Proceedings of the International Colloquium in the Philosophy of Science [held at Bedford college, Regent's Park, London, from July 11th to 17th 1965]. (Reprint. ed.). Cambridge: Cambridge Univ. Press. pp. 244–245. ISBN0521096235.