Experimental Design

An experimental design is a specific strategy employed in research to answer a question of interest. In the field of educational psychology, accumulation of knowledge is based on research. For example, an educational psychologist may wish to address the question of whether or not a specific method for teaching mathematics to primary school children results in superior performance on a standardized test when contrasted with an alternative method. Another educational psychologist might conduct a study to determine whether or not noise negatively affects the reading ability of children whose school is situated in close proximity to an airport.

The three research strategies typically employed within the discipline of educational psychology are observational research, the experimental method, and correlational research. Whereas observational research is typically informal and subjective, the experimental method is formal and objective. Alternatively, whereas the observational method sacrifices precision for relevance, the experimental method sacrifices relevance for precision. The use of the term precision in defining the experimental method implies the two elements of control and precise quantification, both of which are lacking in observational research. On the other hand, the use of the term relevance in defining observational research reflects the fact that the latter method observes human behavior in the natural environment as opposed to studying it in under the artificial conditions associated with the laboratory experiment. A hybrid of observational and experimental research is the field experiment, which attempts to utilize experimental methodology to study behavior in the real world. Correlational research also attempts to provide some balance between precision and relevance, in that it can quantify the behavior of people in the real world, yet at the same time employ statistical means to impose some sort of control over the phenomenon being studied. The general subject of experimental design is most germane to research that employs the experimental and correlational methods.