Methodology and methods are only part of the story of choosing a research framework. The way you go about collecting and interpreting data is strongly influenced by how you interpret knowledge and truth. This is about the epistemology. In simple terms, epistemology is the theory of knowledge and deals with how knowledge is gathered and from which sources. In research terms your view of the world and of knowledge strongly influences your interpretation of data and therefore your philosophical standpoint should be made clear from the beginning.