C.K. Prahalad and Gary Hamel's 1990 The Core Competence of the Corporation 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. For Prahalad and Hamel, managers need to be able to identify and evaluate their company's unique skill sets, and the technologies that distinguish them from others businesses. How well they then coordinate these elements defines a company's competitive strength and how quickly it can adapt to new challenges. As Prahalad and Hamel showed in their case studies, the critical thinking skill of evaluation - knowing what you do best, how well you do it, and how you might improve - is absolutely central to staying ahead of the crowd.