Case Study Review of self-esteem

The case description's independent variable is self-esteem. The dependent one is college failure, which is measured by the students' grades.

A cross-sectional design was adopted in the investigation. Because it compares variables between two groups, the design is appropriate. It contributes to establishing self-esteem as a reason of grade difference.

The experimenter's observations are supported by the fact that low self-esteem is one of the causes of college failure. This implies that the test and findings could have discovered additional causes of low self-esteem.  The hypothesis of the study may be written as:

 Injecting chlorpromazine leads to increased cognitive functioning in schizophrenic patients.

This hypothesis is directional. It is chosen because, from the case description, the cause-effect relationship between the treatment (drug) and outcome (performance) is predictable.

The study's design is a randomized controlled trial. It is appropriate for the study as it tests the effect of the intervention on study subjects (APA, 2017).

The purpose of the random selection is to ensure that each participant from the population has an equal chance to be part of the sample, hence, the method reduces selection bias (Cooper, 2012).

The independent variable for the study is the chlorpromazine, whereas the dependent one is the cognitive performance of schizophrenic patients. The cognitive performance was measured by schizophrenic patients' one on tasks or stimuli that they were asked to order by the investigators.

Possible confounds in the study include environmental disturbances such as noise, temperature, and light, which may affect the expected results. The variable can be controlled by ensuring that all participants use a room with the same environmental characteristics, such as level of noise, temperature, and quality of light.

Case 3

The case is not justified because it does not provide concrete evidence on whether radar guns are the ultimate cause of cancer among the cases as compared to the controls who are unexposed to the radar guns. Incident records are used to observe the trend of disease in the case, but the researchers do not perform an experiment to test the exposure. Hence, possible confounds are neither identified nor controlled in the study. On the positive side, this type of study is quick and cheap to conduct (APA, 2017).

It is a case-control study, because of matching the cases (police officers) and the control group (park workers). The problems with this kind of study are the potential bias because of use of recall data and selection, especially of the control group. This study invites many confounds because of the design weaknesses (APA, 2017).

The study can be improved by introducing randomization in the selection of participants, and also by practically testing the effect of exposure to the outcome in a controlled experiment environment.

References

APA. (2017). Ethical principles of psychologists and code of conduct. Retrieved from http://www.apa.org/ethics/code/

Cooper, H. (2012). Research methods in psychology. In APA Handbooks in Psychology Series.