Week 4 Flashcards
What is ‘selection bias’ a threat for & why?
internal validity - participant different to non-participants
What is ‘selection effects’ a threat to & why?
external validity - generalisability to other populations
What is ‘reactive effects’ a threat to & why?
external validity - response to being in a study (HAWTHORNE EFFECT)
What is ‘measurement effects’ a threat to & why?
external validity - meaurement and testing affecs gernalisability
Reliability addresses…
a repeated measurement of assess providing a consistent result given the same cirrcustances
The Hawthrone Effect is?
A participants response of being in a study
What does it mean if a outcome is ‘meaningful’?
outcomes are credible, meaningful and related to the issues
What does it mean if a outcome is ‘measureable’?
Aendable to dependable measurement in some way
What does it mean if a outcome is ‘responsive’?
change that occurs is demonstrated in outcome measure
What are the 6 threats to Internal Validity?
History Maturation Testing Instruentation Mortality Selection Bias
What are the 3 threats to external validity?
selection effects
reactive effects
measurement effects
What is ‘History’ a threat for and why?
internal validity - events happening outside of a study
What is ‘Maturation’ a threat for and why?
internal validity - changes over time
What is ‘Testing’ a threat for and why?
internal validity - changes due to experience of test
What is ‘Instrumentation’ a threat for and why?
internal validity - changes in measurement rather then change in status
What is ‘Mortality’ a threat for and why?
internal validity - people dropping out of study
What is the main outcome for a study called?
primary outcome
What are the secondary outcomes?
other outcomes of intrest
What 5 things make a ‘appropiate’ outcome
Meaningful Measuable Responsive Valid Reliable
What is reliabilty?
whether repeated measurement of assessents will provide a consistent result in same circcusatnces
What is validity?
do you measure what you intend to measure
What is internal validity?
study results legitmate because of the way the study was constructed
What is external validity?
whether results are transferable to other groups
Whats another nae for ‘external validity’?
generalisability
Whats the effect of not being internal validity?
you cannot have external validity
