Test 2 Lecture and Chapter Material Flashcards
(69 cards)
What is experimental research designed to do?
establish a cause-effect relationship between an independent variable and a dependent variable
What are the three classifications of experimental research?
1) True Experimental
2) Quasi Experimental
3) Pre-experimental
What are the three essential characteristics of true experimental research?
1) Manipulation of an independent variable
2) Control (alternative) groups
3) Random Assignments to Groups
What is the purpose of random assignments to groups?
- Each participant has an equal chance of being assigned to any group
- Increases the likelihood that the groups will be equivalent on key characteristics at baseline
- Controls for most threats to internal validity.
- Researchers must still do best to minimize the threats of history, instrumentation, and mortality
What are the types of true experiment designs and their symbols?
Control group: G1: R D1 T D2 G2: R D1 D2
Two Group: G1: R D1 T1 D2 G2: R D1 T2 D2
Multi-Group: G1: R D1 T1 D2 G2: R D1 T2 D2 G3: R D1 D2
Why do some True Experiments have only a post-test design? What’s the concern?
- Want to know response to something can only test for it after have intervention
- Concern: Cannot do a statistical test to affirm group equivalency
What are the characteristics of Quasi-Experimental Research Designs?
- No random assignment (already in groups)
- Control Group OR multiple measures
What are the types of Quasi-Experimental Research Designs?
- Nonequivalent Control Group Design
- Repeated Measures Design
- Time Series Design
What is the symbol pattern, use, and major threat/minimization strategy to internal validity for nonequivalent control group design?
G1: D1 T1 D2 G2: D1 T2 D2
- Use: When person-factors (IQ, personality, habits) are the independent variable: not ethical or feasible to manipulate
- Threat: Selection Bias
- Minimize: match groups by relevant variables and statistically compare
What is the symbol pattern, use, and major threat/minimization strategy to internal validity for repeated measures design?
T1–D1–T2–D2–T3–D3 (each person becomes own control)
- Use: small sample size
- Testing
- Minimized: allow for adequate rest between exercises, randomized order of tests
What is the symbol pattern, use, and 2 major threats/minimization strategy to internal validity for Time Series Design?
D1 D2 D3 {Pre-test} T D4 D5 D6 {Post-test}
- Use: See change overtime, effect of policies or rules
- Threat: History & instrumentation
- Hard to control for
How do quasi experiments relate to external/internal validity? Why?
Tend to have stronger external validity (occurs in real-world situations)
Tends to have weaker internal validity (due to lack of randomization)
What are strategies to reduce internal validity threats in Quazi-Experimental tests.
1) Matched Groups
2) Test (statistically) for group equivalence
3) Larger groups
What are the characteristics of pre-experimental designs?
- No random assignment
- Only one group OR 2 groups without multiple measures (May not have control group)
Explain how descriptive research differs from experimental research.
Descriptive research differs from experimental research in that there is no manipulation of an independent variable rather there is an examination and characterization of an interest group
Why would a researcher want to perform descriptive research?
To understand the characteristics of a certain group to guide decisions related to interventions.
Under what situations would a researcher want to use a case study?
When the researcher wants more detail about an individual, group, situation, or therapeutic or educational setting than a questionnaire or even an interview can provide
How do case studies differ from observational research?
Case studies use self-reported measures and typically very in-depth on a single individual, but not generizable while observational research uses the researcher’s observations.
What developmental research designs involve the study of a group of participants over a long time? Please provide a brief summary of this type of research design.
Longitudinal design.
This research design follows a small group of individuals over a long period of time (months or years) to determine and describe the change in the group’s characteristics over time.
What developmental research designs involve the study of participants from different age groups over a short time? Please provide a brief summary of this type of research design.
Cross-sectional designs
Researchers study participants of different age groups at one point in time to determine and describe the effect of development.
In what key ways do epidemiology and experimental research differ?
They differ in that epidemiology focuses on population and gathers data from a large heterogeneous sample whereas experimental research focuses on internal validity and gathers data from a small homogenous samples.
What are the types and symbols of Pre-Experimental Designs? What are the problems and uses for Pre-Experimental Design?
- One Shot Study Design: T D
- One Group Pre-test Post-test Design: D1 T D2
- Static Group Comparison: G1: T D
G2: D
Problems: Control few threats to internal validity, inconclusive determination of cause and effect relationships
Valuble For: Pilot Study, Exploratory Study
What are the types of close-ended questions? What are the considerations?
Dichotomous (yes/no)
Scaled
Check Lists
Ranking Questions
Considerations:
1. Responses should be exhaustive (should include all possible answers)
2. Responses should be mutually exclusive (each choice should represent a unique answer)
Where might it be suitable to incorporate open-ended questions in a quantitative survey? Considerations?
- Elaborate on answer, at end of survey, impossible to have exhaustive responses
- Make sure there is enough space and wordiness is decreased, ask one question at a time.
