Exam #2 Flashcards
(51 cards)
Experimental and Quasi-Experimental Designs
-Researcher intervenes
-Tests cause-effect
-Provide Level 2 and 3 evidence
True Experimental Design Properties
- Randomization
- Control
- Manipulation
Often called Randomized Controlled Trial (RCT)
Control
Acquired By
-Manipulating independent variable
-Random assignment
-Using control group
-The control group receives the usual care or a placebo
Treatment Effect
Effect attributed to the intervention
Effect Size
Statistical measure of the strength of the relationship between two variables
Power Analysis
-Informs researcher of SAMPLE SIZE NEEDED to determine of the effect intervention
Types of Experimental Design
- Randomized controlled trial
- Solomon four group design
- After only design
Randomized Controlled Trial
-use experimental and control groups
-Intervention Fidelity: every subject receiving the intervention receives the same intervention
-Statistical comparisons to determine any differences between groups
-Healthy sample size
After-Only Design
-AKA Post-test only control group design
-Two random groups, neither is pre-tested
-Used to minimize testing effects or when pretest isn’t possible
Strength of Experimental Design
Most powerful for testing cause and effect
Weakness of Experimental Design
-complicated to design
-Costly to implement
-difficult to implement
Quasi-Experimental Design
-Tests CAUSE and EFFECT
-Randomization may not be possible, or may not be control group, or neither
Provides LEVEL 3 evidence
Types of Quasi-Experimental Design
-Nonequivalent control group design
-After-only Nonequivalent control group design
-One Group (pretest-posttest) design
-Time series design
Nonequivalent Control Group Design
-No randomization
-Can compare two groups on variables of interest before the intervention
-Threats to internal validity include selection, maturation, testing, and mortality
After-Only Nonequivalent control group design
-Assigned experimental and control groups, but neither is pretested or measured
-Useful when testing effects are suspected to be a major threat to internal validity
-No randomization
-AKA Posttest only
One-group only (pretest-posttest design)
-When only one group is available for study
-Only an experimental group; data is collected before and after an experimental treatment
-No control group, no randomization
Time-Series Design
-Design is useful for determining trends over time
-Data is collected multiple times before the intervention to establish a baseline
-Data collected multiple times after to determine a change from baseline
Strengths of Quasi-Experimental Design
-Practical
-Less expensive
-Generalizable
-More adaptable to real-world settings
-Replication of study can strengthen evidence
Weaknesses of Quasi-Experimental Design
-Less control –> less confidence
EMIC View
-researches enters participants world
-view of the person experiencing phenomenon
-what is it like to experience phenomenon or to be a part of specific culture or group?
EMIC View elements
-recruit key informants
-use quotes
-Insiders perspective
ETIC
researcher uses QUANtitative analyses of behavior
Qualitative Research Methods
-Phenomenology
-Grounded theory
-Ethnography
-Community bases participatory research
-Case study
Phenomenological Method
Learning and constructing the meaning of human experience through intensive dialogue with people who are living the experience
