Quantitative Research
This paper will identify the quantitative research design employed as well as threats to validity in a study by Weng et al. (2012). The study is entitled “Is there any relationship between dietary patterns and depression and anxiety in Chinese adolescents?” It sought to determine the link between major dietary patterns and the risk for symptoms of anxiety and depression among adolescents.
The study employed a correlational research design. Correlational research designs are quantitative research designs where the researcher has no control over variables. In addition, participants are not assigned randomly to treatment conditions. These designs are used to infer causal relationships between variables. In the study, the correlational design was used to examine the association between dietary patterns and anxiety and depression in Chinese adolescents (Polit & Beck, 2008, p. 272). This association was determined through factor analysis of data on the dietary patterns and presence of symptoms of anxiety and depression in the adolescents. This data was collected through self-reported questionnaires filled by the participants of the study.
Regarding the issue of threats to validity, the study design used is prone to the effects of confounding variables which threaten the internal validity of the study. The study employed a cross-sectional correlational design. As such, its conclusions are limited to aetiological inferences (Thompson et al., 2005). The observed relationship between snacks and animal diet and anxiety and depression thus needs to be interpreted with caution. This is because the poor choices of foods may be a compensatory mechanism for mental problems rather than a causative factor. Social desirability bias and recall bias may also have influenced the findings of the study as it was based on self-reported measures. The two types of biases weaken the internal validity of a study. In the present study, they increase the probability of underreporting of eating patterns and presence of mental disorders (Hassan, 2005). The external validity of the study is also limited. This is because the participants of the study were recruited from an urban town and mainly from one nationality. Therefore, the findings of the study cannot be generalized to all Chinese adolescents.
In summary, this paper has established that a correlational research design was used in the Weng et al. (2012) study. Further, it has identified three threats to the internal and external validity of the study. These threats include confounding between variables, recall and social desirability biases, and characteristics of the sample used.
References
Polit, D. B. & Beck, C. T. (2008). Nursing research: Generating and assessing evidence for nursing practice. Philadelphia, PA: Lippincott, Williams, & Wilkins.
Thompson, B., Diamond, K. E., McWilliam, R., Synder, P., & Synder, S. W. (2005). Evaluating the quality of evidence from correlational research for evidence-based practice. Exceptional Children, 71(2), 181-194.
Weng, T. T., Hao, J. H., Qian, Q. W., Cao, H., Fu, J. L., Sun, Y., Huang, L., & Tao, F. B. (2012). Is there any relationship between dietary patterns and depression and anxiety in Chinese adolescents? Public Health Nutrition, 15(4), 673-682.
