Size effect is a quantity used to determine the impact of an effect in a population, while considering independent details in a study (Cohen, 1992). On the other hand, power is an important factor in studies used to determine significance of the study. An estimation of power in experimental designs can be useful in deciding a sample size. This study will use scenario 2 to evaluate power and size effects. This scenario provides a study by Whiston and Quinby. The study is a literature review investigating impacts of school counseling.
Developing techniques, theories and interventions for use in counseling practice based on the findings on the study by Whiston and Quinby, it is necessary to know the power and the size effects of the contributing studies. Responsive services incorporated in school counselling programs analyzed in the studies determines the effect size of the review. From the study, it is important to note that school children in elementary level respond effectively from services addressed to help them with effect size of 39. However, most of the studies had an effect size of 35. The literature investigation also analyzed 10 studies that examined the impacts of responsive services in high school students. From the 10 studies, there was an effect size of 22 while another study exploring the same has an effect size of 35. From the analyzed studies, the effect sizes of the studies fall below the favorable size which is 39.
Other studies analyzed impacts of responsive services when counseling is done in individual and group counseling. Findings from the studies did not provide a clear divide line on the most effective method. From the literature review, a study by Prout and Prout (1998) noted that most of the studies analyzing counseling and psychotherapy focused on group intervention. The study also noted that Whiston et al. (2007) found that group interventions produced an effect of 35. While individual counseling was investigated by only three studies. The literature study found individual counseling effective as opposed to group counseling. A major challenge with these studies is their old age. Age of a study may not be applicable due to the dynamics involved in various aspects of events.
The chances that this study finds statistical relevance is dependent on its sample size. According to Cohen, (1992), big sample sizes are more effective because they are able to detect small similarities or differences that may be important. The study by Whiston and Quinby did not pin point on the exact number of studies it analyzed. An assumption may be made that the study had a big sample size being that it analyzed studies with different designs ranging over a long period of time. This factor adds on to the advantage of increasing the power of the study.
In conclusion, the size effect can be described as the actual finding in a study, while power can be used to determine effect in the study (VanVoorhis & Morgan, 2007). For this reason, one can summarize that matters on school counseling services have not been thoroughly researched. Biasness in studies can also be noticed, where most of the studies focused on group counseling and very few looked into individual counseling. Studies with valuable effect size are old and have problems with their methods. A scholar practitioner may not consider adopting results from this study in practical counseling.
References
Cohen, J. (1992). Statistical power analysis. Current directions in psychological science, 98-101.
VanVoorhis, C. W., & Morgan, B. L. (2007). Understanding power and rules of thumb for determining sample sizes. Tutorials in Quantitative Methods for Psychology, 3(2), 43-50.
Whiston, S., & Quinby, R. (2009). Review of school counseling outcome research: Psychology in the Schools, 46(3), 267-272. Retrieved from Academic Search Complete database.