In order to comprehend the practical significance of research findings, a researcher needs to consider power and effect size. Including power and effect sizes into a study enables readers to better contextualize and interpret findings(Huberty, 1987). Additionally, including ES facilitates better-quality research reviews, assists future researchers develop more specific parameters, and aids in comparing the present research to past ones (Thompson, 2000).
In the study, five modalities are analyzed: individual counseling, group counseling, referral, consultation, and peer assistance programs. In the Whiston study, the overall ES was higher (.35) than the individual ESs, and this is attributable to the fact that the overall findings utilized more studies which were also more heterogenous (including elementary, middle school, and junior high students.) The small ES of .22 with middle or junior high students is attributable to the fact that only 10 studies assessed the effectiveness of interventions, indicating that the small ES is as a result of limited reliability on the measurement instruments (Past studies).
While analyzing the difference between individual and group counseling there are different ESs which leads to mixed results on whether to use group or individual counseling. Group counseling is often evaluated(hence the higher ES) while only few researches focus on individual counseling (Whiston et al., 2009). The results of the studies are, however, taken with caution due to conflicting findings by the researchers as well as the research designs used which have a significant influence on the ES(Olejnik & Algina, 2000.) The support for group counseling is compounded by the fact that numerous other researchers including Borders and Drury (1992) conducted research on group counseling. This compounded with the fact that they are more heterogeneous and focus on different issues leads to more reliance on the results for group counseling.
The studies on individual counseling are limited which increases the likelihood for bias. I t is hard to draw conclusions on the other modalities (referral, consultation, and peer assistance programs) due to the lack of research on the area.
Huberty, C. J. (1987). On statistical testing. Educational Researcher, 16, 4-9.
Olejnik, S., & Algina, J. (2000). Measures of effect size for comparative studies: Application, interpretations, and limitations. Contemporary Educational Psychology, 25, 241-286.
Thompson, B. (2000). A suggested revision to the forthcoming 5th edition of the APA publication manual
Whiston, S., & Quinby, R. (2009). Review of school counseling outcome research. Psychology in the Schools, 46(3), 267-272.