5 Reliability and validity

Validity

If something is valid then that suggests that it is true. For small-scale, qualitative research then clearly the knowledge produced cannot to be tested to see if it is true, but this does not mean that qualitative research is not worthwhile. We have to think about the concept of ‘validity’ in a different way. Bassey (1999) suggests that trustworthiness can be considered to be a measure of validity. These are some of the things we need to consider (Cohen et al, 2003).

• Can the results be generalised? Someone who hears about or reads about your research might decide that, based on their experience then it is authentic and seems sensible.
• Does the data support the conclusions? This is more likely if there is more than one source of data collected over a period of time or if the findings have been checked with the participants.
• Do the questionnaire or interview questions relate clearly to the research questions?

Reliability

Reliability is a difficult concept when applied to qualitative research, as it is to do with repeatability and replicability. Clearly, two people carrying out the sorts of projects described in this unit are unlikely to produce exactly the same results.

Reliability in qualitative settings includes fidelity to real life, authenticity and meaningfulness to the respondents. Cohen et al. (2003) suggest that the notion of reliability in naturalistic settings should be construed as ‘dependability’ and achieving dependability relies on many of the ideas already discussed, such as collecting enough data, checking your findings with the participants, and looking for evidence of the same idea from more than one data source.