ABSTRACT
The goal of research design is to create a logical basis for drawing sound conclusions. Remember to consider the possibility of indirect causes in developing theories for research and to identify possible intervening variables. A variety of other research designs build on the logic of the classic experiment but add modifications that are especially relevant in the social sciences. In field experiments, researchers must use careful selection of the subjects and random assignment of subjects to the test and control groups in order to gain control over background characteristics that may influence results. Most of the research schemes employed by political scientists can be classified as quasi-experimental designs. In time-series designs, the researcher makes several observations both before and after the introduction of a causal phenomenon and compares values on the dependent variable before and after. The researcher's task is to determine whether the general post-crackdown trend is significantly different from the general pre-crackdown trend.
