How to decline answering details about my thesis? I am a graduate student studying Education. I am currently working on my thesis, am about half-done with this and I expect to finish in one year. For the research, I am visiting classrooms at various public schools.

Recently, one such public school asked that, in exchange for letting me visit, I share my advice about teaching. Since they welcomed me their classroom, I did not see much of a problem with this and did not think that would present any problems. I prepared an outline for a 90-minute discussion covering some areas, drawing somewhat on my findings related to my research. After sending this off to them before the lecture, I found they are quite disappointed and want far more from me, essentially they want the very core of my thesis.


Is it acceptable practice for graduate students to be guarding of their work? Is this common enough that I can cite it as a reason for wanting to avoid sharing the details?
The one valid point I can see here(*) for not sharing the state of the thesis:


  For the research, I am visiting classrooms at various public schools.


You should not share the preliminary details of your thesis if this could affect the outcome of your study.
As I understood the question, the school (or some teachers or students) may be the subjects you study, so they should be as little influenced by you as possible (that is, don't tell them that they are in the placebo group).

(*) things would be different e.g. if you were in an engineering field and working towards a patent