A philosophical assumption is the theoretical framework used by researchers to collect, analyze and interpret the data that is collected in a particular field of study. It establishes the background used for coming to conclusions or decisions.
There are three types of philosophical assumptions that are used to develop research methodologies. Ontological assumptions refer to the nature of reality of the subject that is being researched. It can include multiple realities and multiple forms of evidence. Epistemological assumptions deal with subjective evidence that is collected from field studies. Axiological assumptions take into account the biases of the researcher and actively report them. In behavioral and social research, they can be used to establish whether the environment being studied is a product of the behavior that is encountered or if the behavior is a product of the environment.