Widen your reading list with the materials listed below.

Seale, C. (1999b). Quality in qualitative research. Qualitative Inquiry, 5(4), 465–478. Retrieved from http://journals.sagepub.com/doi/pdf/10.1177/107780049900500402

Meyrick, J. (2006). What is good qualitative research?: A first step towards a comprehensive approach to judging rigour/quality. Journal of Health Psychology, 11(5), 799–808. Retrieved from http://journals.sagepub.com/doi/pdf/10.1177/1359105306066643

Decker, S. H., & Pyrooz, D. C. (2010). On the validity and reliability of gang homicide: A comparison of disparate sources. Homicide Studies, 14(4), 359–376. Retrieved from http://journals.sagepub.com/doi/pdf/10.1177/1088767910385400

Walwyn, R., & Roberts, C. (2010). Therapist variation within randomised trials of psychotherapy: Implications for precision, internal and external validity. Statistical Methods in Medical Research, 19(3), 291–315. Retrieved from http://journals.sagepub.com/doi/pdf/10.1177/0962280209105017