Research Design
The purpose of science is to establish knowledge. Research is an approach to drawing scientifically based and sound inferences about a desired outcome based upon the impact of a variable of interest. Although a number of research methods are available, they have in common careful observation and systematic evaluation of the subject matter under varying conditions. The diverse methods constitute special arrangements and plans of observation that are designed to uncover relations between variables in a relatively unambiguous fashion.
However systematic, the results of research may not necessarily reflect the effects of the manipulated variables. Instead, they may by a function of unspecified factors extraneous to the manipulation itself, such as the setting and experimental arrangement in which the result was obtained. Because controlling for all possible factors can never be realized, minimizing the effect of non-experimental factors is the primary task of research methods and the goal of a given experiment.
Methodology is directed at planning an experiment in such a way as to rule out competing explanations of the results. The better an experiment is designed, the fewer the alternative plausible explanations that can be advanced to account for the findings. By controlling or holding constant sources of influence that might vary under ordinary circumstances, the relation between the variables of interest can be examined. Ideally, only the effects of the independent variable could be advanced as the basis for the results. We shall discuss several methodological features designed to maximize clarity of the findings.
