The term 'relativism' is frequently either a term of abuse used by critics of constructivism (notably realists, for whom it may refer to any epistemological stance other than realism) or by constructivists themselves referring to a position whereby 'anything goes' with which they do not want to be associated. Critics associate relativism with an extreme idealism or nihilism denying the existence of a real material world - which it does not necessarily entail. Since few theorists choose to label themselves relativists it is difficult to define the term adequately. One characterization is as the stance that there are numerous alternative versions of reality which can only be assessed in relation to each other and not in relation to any 'absolute', fixed and universal truth, reality, meaning, knowledge or certainty.