Students will be able to:

1. Explain how the nine threats to internal validity can impact the results of research studies and how they can or cannot be controlled. (You should know these nine threats and be able to give practical examples. Random assignment is critical.)
2. Explain how the four threats to external validity can impact the results of research studies and how they can or cannot be controlled. (You should know these nine threats and be able to give practical examples. Random selection is critical.)
3. Explain through the use of practical examples, the limitations of preexperimental designs. (Lack of randomization makes findings about the treatment inconclusive.)
4. Explain through the use of practical examples, the advantages and disadvantages of each of the three experimental designs. (Randomized groups, pretest/posttest, and Solomon designs are all true experimental designs but allow different comparisons.)
5. Explain through the use of a practical example, the advantages and disadvantages of using a quasi-experimental design. (Can use preexisting groups, lack of randomization, etc.)

(Revised 1/18/98)