Quasi-Experimental Designs While true experiments contain the highest degree of control, they are not always possible in some situations. Quasi-experiments are similar to experiments in that they...

Quasi-Experimental Designs means resembling the experimental research but it is not true experimental research. There is manipulation of independent variables and participants are not assigned randomly to the conditions (Cook & Campbell, 1979). Before the measurement of dependent variable, there is manipulation of independent variable in such experiments resulting in elimination of directionality issue. Further as there is no random assignment of participants, it makes that there are other variations between conditions and issue of confounding variables is not eliminated. Thus, validity of these experiments is between true experiments and the correlational studies. These are conducted mostly in field settings where it is impossible or very difficult to assign randomly. They tend to evaluate the effectiveness of a treatment mostly. Some of quasi experiment designs include nonequivalent group design, pretest-posttest design, interrupted time series design, combination designs, pretest only design, regression discontinuity, etc. (Dinardo,...