The article Cholesterol and Human Health uses a non-experimental quantitative research design to establish the effects of varying cholesterol levels on the heart and their overall health effects on human beings. A detailed overview of the nature of cholesterol and its composition is provided in the article (Ma, 2006). The article provides a detailed discourse of the significance of cholesterol and its effects on the human heart. An investigation on the effects of different drugs on people suffering from both good and bad cholesterol was established. Here, an ex post facto investigative design demonstrates the quantitative aspects of the study (Trochim, 2006a). The approach enabled the researcher to identify the presence and effects of external interactions which were important in solving the problems caused by the threat to external validity. Here, a critical assessment of the non-experimental nature of the research design revealed that the researcher could not manipulate the independent variable (Trochim, 2006b). The researcher wanted to demonstrate the effects of the dependent and independent variables on the outcome of the results. According to Trochim (2006a), the research confirmed the reliability of the non-experimental nature of the investigation because it lacked the aspect of randomness. Here, there was evidence of the existence of causality between the dependent and independent variables. The variables were not easy to manipulate as well (Trochim, 2006c). Besides, the level of complexity was noted to vary among the variables as well. Trochim (2006c) notes that the efficacy concept and naturalistic settings were introduced into the study to make internal validity hold. In addition to that, the study was made effective to address the problem of external validity.
References
Ma, Hongbao. (2006) Cholesterol and human health. The Journal of American Science, 1(2), 46-50
Trochim, W. (2006a). Research methods knowledge base. Designs. Web.
Trochim, W. (2006b). Research methods knowledge base. External validity. Web.
Trochim, W. (2006c). Research methods knowledge base. Introduction to validity. Web.