Subjectivity

I was very interested in Kumashiro's point about "good" knowledge and teaching.  To describe "good" teaching, he says it is what makes taking "effective," "successful," "desired," and "valued."  Kumashiro argues that "good" teaching is comfortable, but it often furthers oppressive structures and blinds teachers to the problems that they do not want to see.  What I notice most in these descriptions, though, is the subjectivity of each adjective.  How is effectiveness and success measured? Who is the one that determines what is desired or valued?  Obviously, just in these word choices there are voices silenced.  My question, I suppose, is how to enact change, when the system itself is not changing?  When Kumashiro speaks of his time in Nepal, he said that there were many students who felt that they were going fail the tests and not pass on to the next grade level because he was changing what they were teaching.  This seems like a legitimate concern.  How can a teacher try to change from teaching "good" knowledge to teaching "troubling" knowledge without putting them at risk with the system that they are in?  This was very obvious in the case of standardized testing and in a system that we see as 'foreign' and maybe outdated, but this is also a problem in the US with other topics.  For instance, there are still very different ways to teach about social issues all over the country, and while a teacher might want to change how they are taught, parents and administration often stand in their way.  I suppose in the end, that what is good teaching is always subjective, no matter the content, and there will always be disagreement.  The best solution that I can come up with to this problem is to employ Freire's belief that dialogue is the best way.  Subjectivity is a part of life, but presenting many different viewpoints without espousing one way as correct seems to be the best way to compromise the changing system.