In the last chapter we saw that evaluating the usefulness of a test can be a complex process, part of which is the evaluation of the evidence presented to support a validity argument. However, just the fact that we have placed so much emphasis on the quality of the evidence requires some comment. Language testing researchers are increasingly understanding that what they do and how they do it requires a philosophical basis, and this is not only within the growing field of ethics in language testing (see Language Testing, 14(3)). One of the most appealing epistemologies for modern language testing is Pragmatism (Davidson and Lynch, 2002: 121; Oiler et al, 2000a, 2000b, 2001). Peirce (1905: 264) wrote that

if one can define accurately all the conceivable experimental phenomena that the affirmation or denial of a concept could imply, one will have therein a complete definition of the concept, and there is absolutely nothing more in it.