C.K. Prahalad and Gary Hamel’s 1990 helped redefine traditional ideas of management strategy. It did so by focusing companies on one of the key critical thinking skills: evaluation. In critical thinking, evaluation is all about judging the strengths and weaknesses of arguments – assessing their reasoning and the relevance or adequateness of the evidence they use. For Prahalad and Hamel, companies could gain a competitive edge by evaluating themselves: their own strengths and weaknesses. By sensitively evaluating core competencies – the collective knowledge inside the organization that distinguishes it from other corporations – they could target efforts and resources with strategic focus.