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Quasi-experimental Research Design

The foundation of both observational research and experimental design methods each contributes significantly to the study and practice of public health.

1.What are the strengths and weaknesses of the research methodology presented in Brownson et al. (2007)?
2.What value did using a quasi-experimental design add to the research study?
3.How does this impact the validity of the research project?
4.What do you believe is the best strategy for disseminating research results? Support your position

Reference :
Brownson, R., Ballew, P., Brown, K., Elliott, M., Haire-Joshu, D., Heath, G., et al. (2007). The effect of disseminating evidence-based interventions that promotes physical activity to Health Departments. American Journal of Public Health, 97(10), 1900รข?"1907.

This article presents research findings from a study that explored the effects of disseminating evidence-based practices with the goal of promoting physical activity. This article offers a firm example of research reporting in the field of public health.


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Dear Student,

In providing my response, I have included some definitions and brief explanations that are relevant to understanding this article and what the problem questions are asking. Furthermore, I have tried to guide you in such a way that you will not only be able to better evaluate and understand the specific article but also research methodologies in general.

The key difference between observational and experimental designs is that an experimental design is one whereby exposure to a variable is controlled (independent variable) whereas in observational studies, there is no control over exposure. Typically, in experimental studies - there will be two groups, but only one group will be exposed to the independent variable, and the differences (if any) in outcome (which are the dependent variables) between the two groups is assessed. The assignment of persons to each group should ideally be random. Where random assignment is not possible, the two groups should be as closely matched as possible. Experimental research design is considered the gold standard in research methodology because unlike observational methodology, it has an increased ability to determine causation as it shows that
? exposure preceded outcome
? and has the potential to show consistency in outcome (as the exposure is controlled)

A quasi-experimental design follows these basic ...

Solution Summary

A specific article that outlined a quasi-experimental design for determining the best strategies for dissemination of research findings was used as an example to highlight the strengths and weaknesses of quasi-experimental design, including references to internal and external validity of these designs.