Sorensen, vagueness and educational assessment : the significance of vague borderline cases

• Main Author: Marshall, Richard Henry
• Published: University College London (University of London) 2012
• Subjects: 371.26
• Online Access: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.572974

This thesis defends objections derived from current high stakes educational summative assessment arrangements. The objections are derived from considering consequences of the philosophical problem of vagueness. I argue that current arrangements unsuccessfully address the issue of vagueness but have done so fully recognising that vagueness is no trivial threat to assessment practice. The issue stands alongside other issues considered of equal significance to fairness and equality as other key issues addressed in educational assessment literature such as reliability and validity. Vagueness raises peculiar problems about borderlines that are typically understood through consideration of the standard puzzle of vagueness, the sorites. The puzzle asks why, if ten thousand grains of sand make a heap, one grain doesn't? Although deceptively simple and of ancient pedigree, this puzzle has continued to prove difficult to solve and there is no settled account amongst contemporary philosophers as how best to conceptualise the phenomenon. Pressed into service of educational assessment, we can adapt the sorites to ask: 'If 100 marks is a pass, why isn't one mark?' The problem is that wherever one decides to draw a sharp boundary between pass and fail at any particular mark, there seems no justification for not drawing it at just a slightly lower or slightly higher one. Vagueness threatens the system because it provides reasons for thinking that no one should fail. If the puzzle is set up in reverse, it also provides reasons for thinking that no one should pass. I presuppose that any assessment system unable to offer principled rational discriminations of value is incompetent. The sorites carries this threat. My thesis- presses a concern that, because of Cresswell's powerful advocacy of a certain approach to vagueness, the educational assessment community has considered his perspective to be the last word. Unfortunately this is not the case. I draw attention to the fact that there are several options and that different consequences for assessment follow depending on which approach is adopted. I argue that the epistemic approach to the issue solves the problem of vagueness using a classical logic framework used in intrasubjective judgment in science. I argue that Roy Sorensen's epistemic solution to the sorites satisfies best the requirements of an assessment systems' need for similar intrasubjective judgment.