Professional discourse provides ideas that add to craft knowledge. Professional experience provides knowledge of what has worked. Subject knowledge is transmuted through craft knowledge into a teachable form. Craft knowledge of teaching determines the practice of teaching. Craft' knowledge of management and politics determines policy formation.
Libraries store and inform educational research.
Usually unrecognised, ideologies impact on knowledge, discourse and research. Fuzzy Generalisations as Sound Bites from Research 'Do y instead of x and your pupils will learn more'. That's pithy and may be memorable. But left like that it is contrary to the truth ethic of research, for it omits the details of context and circumstance which give it meaning and it has a certainty and absoluteness which we all know is never the case. Suppose that instead the researcher said to teachers 'Do y instead of x and your pupils may learn more'.