Full text of Research Methods Knowledge Base (2001) 2nd ed. by William M. Trochim, Cornell University.
A comprehensive Web-based textbook that addresses the topics in a typical introductory undergraduate or graduate course in social research methods. It covers the entire research process including: formulating research questions, sampling, measurement, research design, data analysis, and writing the research paper. It also addresses the issues of validity in research, reliability of measures, and ethics. The text is fully hyperlinked.