Experimental, quasi-experimental, and non-experimental research are distinguished depending on the tasks and methods of studies. Experimental studies have several groups of participants assigned randomly, with the intervention being controlled. In quasi-experimental studies, participants may not be allocated to comparison groups or may not be randomly assigned. In a non-experimental study, there is no manipulation of independent variables and control of constant variables. All types of research can be useful as a theoretic base.
After the experiment, the results of the groups are compared to confirm or refute the hypothesis. The study by Harper et al. (2020) is experimental; researchers compare early screening for gestational diabetes with routine screening in women diagnosed with obesity. Baseline characteristics are balanced between groups, with half of the women having early screening and the other half having routine one (Harper et al., 2020). Experimental design brings the study to a high level of evidence, with a high degree of probability excluding chance.
Quasi-experimental studies may have high evidence levels, but the participant groups are not equivalent, which may lead to inaccuracies. The research by McGovern et al. (2022) is an example of a quasi-experimental study. Researchers use data from a cohort survey of children and their families to track the health of mothers and the economic situation of families (McGovern et al., 2022). McGovern et al. (2022) use interview information combined with baseline sociodemographic characteristics to collect data on depressive symptoms. The study did not identify control groups and did not randomize the sample.
Non-experimental research does not directly focus on the relationships of the phenomena being studied. Qualitative research focuses on the analysis of broad questions and does not apply statistical methods. The study by Lonn et al. (2022) is an example of a non-experimental study that focuses on examining the role of nurses. Data was collected through semi-structured interviews (Lonn et al., 2022). Non-experimental interviews can provide insight into the opinion of the social group of interest on a particular issue.
In conclusion, experimental studies have the highest accuracy of results since the likelihood of bias is reduced by randomization. Quasi-experimental studies are less precise but allow a significant amount of data to be analyzed. Non-experimental research, such as descriptive and qualitative articles, can provide insight into a particular phenomenon and public attitudes toward it. All types of studies are important and useful if the researchers take a scientific approach.
References
Harper, L. M., Jauk, V., Longo, S., Biggio, J. R., Szychowski, J. M., & Tita, A. T. (2020).
Early gestational diabetes screening in obese women: A randomized controlled trial. American journal of obstetrics and gynecology, 222(5), 495-503. Web.
Lonn, B. B., Hornsten, A., Styrke, J., & Hajdarevic, S. (2022). Transitioning to the clinical Research nurse role–A qualitative descriptive study. Journal of Advanced Nursing, 78(11), 3817-3829. Web.
McGovern, M. E., Rokicki, S., & Reichman, N. E. (2022). Maternal depression and economic well-being: A quasi-experimental approach. Social Science & Medicine, 305(1), 1-9. Web.