Agresti, Alan & Finlay, Barbara (2009): Statistical Methods for the Social Sciences, Fourth Edition. Pearson, chapters 1-3. (72 pages)
Booth, Wayne C., Colomb, Gregory G., & Williams, Joseph M. (2003). The Craft of Research (2nd ed.), Ch. 3, 4 (21 pages)
Bryman, Alan (2012): Social Research methods 4th edition, Oxford: Oxford University Press. Ch. 1-7, 17, 20, 21, 23, 26-27. (310 pages)
Creswell, John W. (2009): Research Design: Qualitative, Quantitative and Mixed Methods Approaches. SAGE. third edition. Ch. 1-3 (72 pages)
Kleven, Thor A. (2008). Validity and validation in qualitative and quantitative research. Nordisk Pedagogik n. 3. pp. 219-233 (15 pages)
Howe, Kenneth R. (1988). Against the Quantitative-Qualitative Incompatibility Thesis or Dogmas Die Hard. American Educational Research Association 17: 10. Pp. 10-16. (7 pages)
Merton, Robert K (1973), The Normative Structure of Science. in Merton, R.K. and Norman W. Storer: The Sociology of Science, Theoretical and Empirical Investigations. Chicago: The University of Chicago Press, pp.267-278. (11 pages)
Recommended reading:
Chalmers, Alan F.(1999):What is this thing called science?. Buckingham: Open University Press. Ch. 1-2, 4-10, 14-16. (188 pages)