Research Design Flashcards
Cross-sectional
Data collected once from one point in time
Longitudinal
Data collected repeatedly over a period of time
Retrospective
Historical data
Prospective
Data collected in real time
Degrees of control
Maximal: experimental design
Moderate: Quasi-experimental design
Minimal: Non experimental design
Experimental design format
Purposeful manipulation of a variable (s); random assignment of subjects to two or more groups
Quasi experimental design format
Purposeful manipulation of a variable (s); no random assignment to groups; may have only one group
Non experimental design format
Observational without manipulation of a variable (s); no random assignment to groups; may have only one group
Descriptive research
- No manipulation by researcher
- Results are “tempered” (possibility of bias and lack of control)
- Info readily available
- Studies easy to do and little time
- Provide clues about possible risk factors of disease/conditions
- Clues about outcomes of tx
- Used to generate hypotheses
Ex. cross sectional studies
Types of descriptive research designs
- Case report, case study (both focus on individual
- Case series, cross sectional studies (both focus on groups)
Case Reports (individual)
- A-B design (pre/post measures)
- Deveop of disease or how patient effect by tx
- Need to have whole progression of patient
- Not considered research and don’t need IRB
- Makes a good starting point for future research. Cannot determine “cause-effect”
Case Series (groups)
- n>1
- Most basic research design
- Just longitudinal observation not “cause-effect”
- Detailed description (series of similar patients, their response to tx, etc)
Cross Sectional Studies (groups)
- Compare 2 factors of interest across groups
- Measure 2 factors of interest at one point in time
- Can’t establish time line
- Associating with correlation
- Can’t be used to determine “cause-effect”
Ex. is there an association between daily meat consumption and colon cancer?
Experimental research
- Manipulation by researcher
- Includes “control” or “comparison” group
- Results “definitive”
- Manipulate indep variable to produce effect on dep. variable
- Usuay tests a specific hypotheses
- Can determine “cause-effect”
- Can determine most effect intervention
- Randomization most common way of manipulation
Ex. RCT
Randomization
- Most common way of manipulation
- Pts or subjects allocated to a tx group at random (ex flip a coin)
- Each pt or subject has equal chance
- Should be completed before study starts
- Minimizes bias
