The purpose for a research design is to, provide answers to research questions that are credible. Internal Validity refers to the extent to which the independent variable, and not other extraneous or confounding variables, produced the observed effect. External Validity refers to the extent to which the results can be generalized to other subjects, measures, treatments, procedures, and settings. Only Design has a comparison or control group but no pretest. This design, which is often referred to as quasi-experimental design because it closely approximates the most desirable experimental designs, is commonly used in educational research.
Factorial designs have two or more independent variables.
There are two primary purposes for using factorial designs. One is to see if the effects of a treatment are consistent across characteristics, such as age, gender, or aptitude. Dr. Dan all rights reserved.