ABSTRACT
Qualitative approaches are often criticised by positivists because of the lack of objectivity and generalisability associated with them. Both reliability and validity are questioned, since Cronbach alphas and R2 cannot be computed. It is not the usefulness of qualitative data that is at stake here, but rather the criteria by which the trustworthiness of a qualitative study can be judged. This issue goes beyond the quantitative/qualitative debate, as ‘all research must respond to canons that stand as criteria against which the trustworthiness of the project can be evaluated’ (Marshall and Rossman 1995: 143). There have been several attempts to rethink such terms as validity, generalisability and reliability in different qualitative research paradigms (Denzin 1997; Hammersley 1992; Kincheloe and McLaren 2000; Lather 1993), but Lincoln and Guba’s (1985) typology is most often mentioned. They have developed four criteria for qualitative inquiry that parallel the quantitative terminology. Credibility (which relates to the quantitative criterion of internal validity) refers to how truthful particular findings are. Transferability (associated with external validity) is concerned with the extent to which the research findings are applicable to another setting or group. Dependability (related to reliability) consists of looking at whether the results are consistent and reproducible. Finally, confirmability (associated with objectivity) pertains to how neutral the findings are.
