In sessions 10-12, we are going to learn different types of quantitative research designs and their internal validity. Research design is the logic to link your data analysis with hypotheses to address the research question (i.e. how you are going to organize and analyze your data to test your hypotheses). Session 10 introduces 3 different types of research designs: experimental design, quasi-experimental design, and non-experimental design. It also discusses the threats to internal validity when you use different designs. Session 11 gives a more detailed introduction to the experimental design. Session 12 demonstrates different quasi-experimental designs and non-experimental designs.
*Note: Questions in Discussion 5 focus on readings in Session 10. Materials in Session 11 & 12 provides supplementary readings, which provides more details about each type of research design.
Please read Trochim Chapter 7 (in Session 10) and answer question #1 and #2.
1. In Trochim Chapter 7 (7-2), it introduces three different types of quantitative research designs, which are experimental design, quasi-experimental design, and nonexperimental design. (1pt)
1) Describe the basic elements (i.e. treatments, # of groups, assignment to the groups, time frame for observation) for each design.
2) Then discuss: What are the major differences between these three types of research designs?
2. Please list three threats to internal validity in each of the following categories and use an example to illustrate each threat. (1.5 pts)
– Single-group threats (0.5 pt)
– multi-group threats (0.5 pt)
– Social interaction threats (0.5 pt)
Babbie Chapter 10 (Babbie, E. (2015). The practice of social research (14th ed.). Boston, MA: Cengage Learning.), Chapter 8 introduces the experimental design. Answer question #3 with what you have learned from Babbie Chapter 8.
3. Think about a topic (research question) related to public administration that you think is appropriate to use the experimental design. To be more specific, describe the major components of the experimental research you propose: 1) independent variable & dependent variable; 2) pretesting & postesting; 3) experimental and control groups. (1pt)
4. Article Critique: Krause et al. (2016)
1) What type of design does this paper use? Do they have single group or multiple groups? What is the observation timeframe (i.e. did they observe all the units multiple times or only one time?) (1pt)
2) With the research design you identify in the above question, are there any potential threats to internal validity (hint: you have discussed some threats to internal validity in question #2. Does this paper have any of those internal validity threats? )Do you have any suggestions to address those threats to internal validity? For example, are there any other control variables that need to be added? (1.5pts)
