A concern for generalization dominates quantitative research. For generalizability and repeatability, identification of sample size is essential. The present study investigates 90 qualitative master's theses submitted for the Primary and Secondary School Science and Mathematics Education Departments, Mathematic Education Discipline in 10 universities in Turkey between 1996 and 2007, in terms of "Population and Sample" using document analysis. Coding is used to analyze the data and results are presented by using descriptive statistics. Most of the theses were found to include a few lines of information on population and sample, and a few presented the characteristics of the sample in detailed tables, though without any information on the selection criteria were given. Randomization in random sampling, which is frequently used, was usually limited to unbiased assignment of two classes out of four within a school. No attention was paid to the appropriateness of the sample size and to the analysis techniques employed. Effect size was calculated in only one dissertation, but was not taken into account in the identification of the sample size. Normality tests also indicated some challenges. The effects of sample size on reliability assessment were not taken into account.