Paul Smeyers argues convincingly that "educational research should be seen as a performative intervention': in effect, as a move in a language game. This chapter explores some of the controversial implications of this position, construing it as contributing to a broader philosophical debate about realist and relativist orientations in educational research that raises many issues about research, policy and practice. The challenge for the relativist is to articulate a set of criteria for arbitrating between incommensurable positions. Smeyers, drawing on the later Wittgenstein, adopts the concept of the language game, but does not consider (other than in passing) the radical implications of its deployment in the postmodern literature, most notably by Jean-François Lyotard. Smeyers also (perhaps for lack of space) employs an unproblematised conception of causation to progress his argument. It is suggested that the consequences of fully embracing Wittgenstein and/or Lyotard in educational research would be far reaching, involving more than the embracing of an interpretive paradigm as commonly construed.