Volunteers and their rights

I presume that ethics within my project will not post too much controversy. When it comes to filming the procedures I will adopt a volunteer release and have all participants sign it. The only thing I will be tampering with that might be contravertial is my goal. I am trying to show how indicators are miss-measured. I don't know for sure yet, but this might involve tampering and assumption with available data. I don't think it will be unethical in accordance to the articles we read.