This reference source provides coverage of the various research methods used in the social sciences. Explaining all the major research designs, techniques and data analysis strategies, it also explains each method in terms of its strengths, weaknesses and sources of error. Examples of student assignments are used to demonstrate the practical applications of abstract research principles. The text provides coverage of the key features of a research enterprise, such as quantitative and qualitative research designs, statistics, theory, ethics bias, validity and report writing. New features of this fifth edition include further discussion of fraud and misconduct in science and of qualitative research methods including Q-sort. There is examination of the increased reliance by government and the courts on police science, and introduction of new statistical concepts such as factor analysis and meta analysis. A revised concluding chapter discusses contemporary meta-theoretical issues and conceptual/methodological trends.