Benefits and shortcomings of quasi-experimental design research

¶ … quasi-experimental design revealing the benefits and shortcomings of the research design. The paper also investigates the reasons the quasi-experimental design are used more often than the experimental traditional design. The study reveals that the quasi-experiments are used in educational environment than other research settings.

Benefits and Shortcomings of Quasi-experiments

A quasi-experiment is the type an empirical study that researchers use to estimate the causal effect of an intervention of a target population. While a quasi-experiment shares some similarities with the traditional experimental design, however, the traditional experiment lacks elements to enhance a random assignment. On the other hand, a quasi-experimental design allows a researcher to control the assignment in order to treat condition. The quasi-experiments have some concerns with regards to the internal validity, however, participants still have the equal chance of being placed in the comparison group or intervention group. The quasi-experiment is has both advantages and disadvantages. (Goldberg, 1990).

The advantages of quasi-experiments is that they are easier to set up compared to the traditional experimental design that requires a random assignment of participants. Moreover, the quasi-experimental is able to address the threats associated to external validity because the findings can be applied to a more general population. Additionally, the quasi-experimentation method is efficient in carrying out a longitudinal research that involves a long period. Other advantages of the quasi-experimental design is that it gives a room to a manipulation. Other benefits of the quasi-experiment is that it is able to draw a stronger conclusion, and contribute to the original body of knowledge. (Ellis, & Levy, 2011).

Despite the benefits associated to the quasi-experimental research designs, nevertheless, they are several drawbacks associated to the quasi-experiments. The quasi-experiments have a challenge in achieving an internal validity despite that they may allow a study to be more feasible. Moreover, a randomization is lacking in the quasi-experimental design, thus, and it will be difficult to determine a causal relationships from the conclusion. Moreover, if a threat to the internal validity is stressed, the researcher may not able to have a total control over the extraneous variables. Other shortcoming of the quasi-experiment is its inability to establish a causal relationships between two or more variables. (Ellis, & Levy, 2011).

Fundamental Weakness of the Quasi-experimental Design

The fundamental weakness of the quasi-experimental design is that its internal validity is more inferior to randomized experimental design, this weakness does not matter because a researcher may put more weight on the external validity to offset the weakness of the quasi-experiment. (Trochim, & Donnelly, 2007).

2. Randomly Assign Participants

In an experiment associated to a random assignment, the group has the same equivalents at the beginning or at the end of the study because a random assignment assigns the same chance to a group in a quasi-experimental design to ensure that both control and experimental are equivalent. It is not possible to assume that the group is equivalent at the beginning of the study, however, it is possible to assume the equivalent of the group at the end of the study because the experimental research will differentiate the subject population from the control group, and minimize the threats of internal validity.

3. Explanation and Examples of Particular outcomes of the Study

Trochim and Donnelly (2007) argue that it is able to maintain diverging outcome pattern when control group maintains a consistent posttest- pretest score, while the score has increased from pretest to posttest. In this situation, the selection threat is the internal validity. Other outcome pattern that reflects an improvement in scores between the pretest and posttest makes the treatment group to improve. However, the selection-regression is the most threat to the internal validity.

6, Reason Quasi-experimental designs are used more than Experimental Designs

In the research environment, Quasi-experimental designs are used more for the research design than the experimental design. When it not possible to conduct a feasible or ethical randomized study, the researcher will use the Quasi-experimental designs (Trochim & Donnelly, 2008). For example, a research to investigate the treatment effects of students in a classroom is likely to use the quasi-experimental method. Thus, the teacher is not likely to randomly select students for the experimental and control group in this type of experiment. Moreover, many medical researcher uses the quasi-experimental research to design the study because many of their studies may not be feasible to randomize. (Greenhoot, 2003).

An example of the quasi-experiment is a research carried out by Goldberg, (1990) to assess "the effectiveness of TV advertising directed to children" (Goldberg, 1990 p 445). The author uses the quasi-experiment to assess whether children who expose to high level of TV adverts are exposed to vulnerability. The author is able to reveal that children responds "more positively to product advertised than do children exposed to less American children's TV" (Goldberg, 1990 p 453). For example, "English-speaking children more aware of toys than French-speaking children (F=400.47, p

Conclusion

The paper discusses the application of the quasi-experimental design within the research environment. The study identifies both the advantages and shortcomings of the quasi-experimental research design. While the quasi-experiment is more applicable for different researches, it faces challenges in enhancing the internal validity.

Reference

Ellis, T. J., & Levy, Y. (2011). Framework of problem-based research: A guide for novice researchers on the development of a research-worthy problem. Informing Science: the International Journal of an Emerging Transdiscipline, 11(1), 17-33.

Greenhoot, A. F. (2003). Desgin and analysis of experimental and quasi-experimental investigations. In M.C. Roberts & S. S. Ilardi (Eds.), Handbook of Research Methods in Clinical Psychology (92-114).

Goldberg, N. (1990). A Quasi-experiment Assessing the Effectiveness of TV Advertising directed to Children. Journal of Marketing Research JMR, 27 (4): 445.

Trochim, W. & Donnelly, J.P.(2007). The Research Methods Knowledge Base, (3rd Edition), Mason, OH: Cengage Learning.