There has been much controversy as to the advantages and legitimacy both of quantitative and qualitative research methods in the management area and more widely in the social sciences. There have also been differences as to whether one can combine quantitative with qualitative methods, or whether the two approaches are ‘incommensurable’. It is proposed in this chapter to put forward definitions of each research method; outline their main features; discuss their applications with particular reference to the management area; examine their advantages and disadvantages; set out the critiques regarding each method and whether they are ‘commensurable’ with each other or not. These issues are the subject of this chapter, which involves a discussion as to the preponderance of quantitative research methods in mainstream management scholarship (although there is also a significant number of management scholars using qualitative or mixed research methods). Claims for the legitimacy of quantitative over qualitative approaches because of the scientific methods used in the former are examined in the light of what has been written by prominent historians of science such as Kuhn (1970) and Feyerabend (1993), and social theorists, for example Bourdieu (1990). Ultimately an argument is made for commensurability, complementarity and inclusiveness wherever possible.