There are several different types of research designs. Each design is intended to respond to a particular type of research question. The type of research design depends on the type of research questions asked. For this Discussion, select one of the articles from the reading list and consider several classifications of group research designs.

Post your response to the following: Describe which groups are compared in the research. Then, classify the research design as follows:

1. By explaining whether the study is pre-experimental (cross-sectional, one-shot case study, and longitudinal), experimental (control group with pretest and posttest, posttest only, or four-group design), or quasi-experimental (comparing one group to itself at different times or comparing two different groups)
2. By indicating what the researchers report about limitations of the study
3. By explaining concerns you have regarding internal validity and the ability of the study to draw conclusions about causality
4. By explaining any concerns you have about the generalizability of the study (external validity) and what aspect of the research design might limit generalizability

Post your explanation of what you think the social workers wanted to know when they designed the pre/posttest for evaluating the parenting classes. Be sure to address the concept of attrition and whether or not you believe they took that into account. Be sure to explain why. Then, analyze potential lessons learned from attrition. Finally, explain how you might design a study to gather data about the effectiveness of these parenting classes. Use the following questions to focus your thinking:

• Would you recommend a pre-experimental, experimental, or quasi-experimental design?
• Would the study involve measurement over time?
• Would there be a control group?
• In this group research design you imagine, what or who will be compared?
• What limitations in terms of generalizability and internal validity can you anticipate based on the research plan you envision?
• What can you tell the social worker about the issue of client drop out (also called attrition or experimental mortality)?
• If there is no control group, what type of research design could answer the question: Is this parent training class effective in reducing abusive parenting practices?