HowToDesignAResearchStudy Flashcards
(181 cards)
What are the steps to designing a research design? (How Venerial Disease Overtook My Sexy 3 Aunts Royally)
- Hypothesis
- Variables
- Design
- Operationalizations
- Manipulation
- Setting and Participants
- 3rd Variables (Mediators and Moderators)
- Analyze Data
- Report Results
Hypotheses should be worded as ________ and should make explicit _____ between groups
statements
comparisons
What are the 8 threats to internal validity
- Maturation
- History
- Instrumentation
- Regression Toward the Mean
- Testing
- Selection
- Mortality
- Interaction of Selection x Maturation
Hypotheses should be worded in the past/present/future tense
present or future tense
Describe the internal validity threat: Selection
- Differences in posttest scores exist because of preexisting group differences
- possible unequal distribution of subject-related variables (e.g., sex, race, age, intelligence)
Hypotheses can/cannot be proven
You cannot prove a hypothesis
Describe the internal validity threat: History
- simultaneously occurring outside events may influence subjects
- Events that take place during the course of research that influence the posttest scores
If you include interactions as part of your hypothesis, you need to be explicit about each experimental condition in the interaction. Give an example.
People who work in homogenous groups will perform better than people who work in heterogenous groups
Describe the internal validity threat: Maturation
- Naturally occurring changes in person over time that influence the posttest scores
- Permanent: biological growth
- Temporary: fatigue
What question does the Moderator answer
Answers the question when or for whom does the IV have an influence on the DV
Describe the internal validity threat: Repeated Testing
- Ss may become sensitized
- pretest measurement of the DV may affect the results obtained from subsequent measurements
What question does the Mediator variable answer
- Answers the question how or why does the IV influences the DV
- often a variable that describes an internal psychological mechanism
- Often introduced when there is already a strong relationship between IV and DV
Describe the internal validity threat: Instrumentation
Changes in the way pretest and posttest scores were measured may cause changes in outcome
What should you include when discussing the design of a study
- Name of the design (be specific)
- why it is the best design
- flaws or limitations and how you will attempt to mitigate them
- determine if btwn or within Ss design (state why)
- discuss feasibility (economically, logistically, ethically)
- discuss limitations of feasibility
- design is usually a 2x2 factorial or 2 btwn-Ss factors
Describe the internal validity threat: Regression to the mean
Ss with extreme scores on the pretest will tend to have scores closer to the mean on the posttest
Why do you want to use a 2x2 factorial design
- Economy: the design provides more information from the same amount of work
- Experimental control
- Increases Generality of the results
- A way to investigate interactions among Ivs
*the factorial design allows us to investigate more realistic situations
Describe the internal validity threat: Mortality
Loss of Ss during the experiment that is different btwn the experimental and control groups (e.g., dropping out)
*Differential mortality cannot be ruled out by random assignment
Why is it important to test the interaction of Ivs
Because the effect of an IV rarely occurs in isolation
In the real world, many variables operate simultaneously
Describe the internal validity threat: Selection x Maturation
Differences between groups that cause changes in the groups at different rates
Independent Variable
A manipulation to which participants are randomly assigned (if possible)
What is external validity
The extent to which results fo a study can be generalized from the sample to the population or other settings, samples, and variables
If you cannot manipulation the IV, what types of studies can you do?
quasi-experimental or correlational
Threats to external validity are anything that makes the experimental situation ____
unique
For all levels of the IV, you need to _____
identify the operationalization (even for “absence”)
*be specific (e.g., give quotes of what experimenters will say, if relevant)











