1. Altheide, D.L. & Johnson, J.M. (1994). Criteria for assessing interpretive validity in qualitative research. In N.K. Denzin & Y.S. Lincoln (Eds.), Handbook of qualitative research (pp. 485-499). Thousand Oaks, CA: Sage.
2. American Educational Research Association, American Psychological Association, & National Council on Measurement in Education. (1982). Standards for educational and psychological testing. Washington, DC: American Educational Research Association.
3. Campbell, D.T. & Stanley, J.C. (1966). Experimental and quasi-experimental designs for research. In