Quantitative - data collection issues: outcomes, measurement, reliability, validity Flashcards
What is the main outcome for a study called?
primary outcome
can also have secondary outcomes
What do outcomes have to be?
- meaningful: outcomes have to be credible, meaningful and related to the issue of interest
- measurable
- responsive- change that occurs is demonstrated in the outcome measure
- measurements should be valid and reliable
What is reliability?
addresses whether repeated measurements provide a consistent result given the same initial circumstances
What is validity?
does your measurement, process or assessment actually measure what you intend it to measure?
What is internal validity?
study results legitimate because of the way the study was conducted: did the IV really change the DV?
without internal validity you cant have external validity
What are threats to internal validity?
- history: events happening outside study
- maturation: changes that happen over time
- testing: change due to experience of the test
- instrumentation: changes in measurement rather than change in status
- mortality: differences in study drop out
- selection bias: PPs different to non-PPs
What is external validity?
or generalisability
-concerns whether results are transferable to other groups
What are threats to external validity?
- selection effects: generalisability to other populations, when ideal sample population cant be obtained
- reactive effects: response to just being in a study (hawthorne effect)
- measurement effects: measurement and testing affects the generalisability