The philosophical position referred to as critical rationalism (CR) is potentially important to OR because it holds out the possibility of supporting OR’s claim to offer managers a scientifically ‘rational’ approach. However, as developed by Karl Popper, and subsequently extended by David Miller, CR can only support practice (deciding what to do, how to act) in a very limited way; concentrating on the critical application of deductive logic, the crucial role of subjective judgements in making technical and moral choices are ignored or are at least left underdeveloped. By reflecting on the way that managers, engineers, administrators and other professionals take decisions in practice, three strategies are identified for handling the inevitable subjectivity in practical decision-making. It is argued that these three strategies can be understood as attempts to emulate the scientific process of achieving intersubjective consensus, a process inherent in CR. The perspective developed in the paper provides practitioners with a way of understanding their clients’ approach to decision-making and holds out the possibility of making coherent the claim that they are offering advice on how to apply a scientific approach to decision-making; it presents academics with some philosophical challenges and some new avenues for research. 
Critical rationalism in practice: Strategies to manage subjectivity in OR investigations