9. Reliability and Validity Flashcards
(28 cards)
What is reliability?
The consistency of a measure
What is internal reliability?
The extent to which a measure is consistent in itself
What is split-half reliability?
Comparing results of one half of a test with the other half
What is Cronbach’s alpha?
A test that splits items equally in every way possible to then correlate all halves with the other halves
What is external reliability?
Extent to which a measure varies from one use to another
What is test-re-test reliability?
Stability of a test over time
What is inter-rater reliability?
Used in observational studies
The degree to which different raters give consistent estimates of the same behaviour
What are some ways to improve reliability?
Increase/decrease number of items
Increase sample size
Choosing an appropriate sample
Controlling conditions (consistency)
What is sensitivity?
Detecting a small effect of the IV on the DV
What is the floor effect?
A significant proportion of sample scores are the minimum possible
What is the ceiling effect?
Large portion of the scores are at the higher end of the scale
What is validity?
Whether its measuring what it intends to measure
What is external validity?
Extent to which the results can be generalised to different populations
How can we ensure external validity?
Extend to new populations - replicate with a new group
Representative sample
What is internal validity?
When we can be confident that manipulating the IV affects the DV
What are the three goals of causation?
Shows co-variation/correlation
Shows time-order relationship
Eliminate all possible causes
What are the five threats to internal validity?
- Testing intact group
2.Order/practice/fatigue (participant characteristics) - Extraneous variables
- Unequal loss across group
- Expectancy effects/ demand characteristics
How to control for internal validity?
Control everything
Counterbalance
Randomise
Double-blind
Deception/ naievety
What is ecological validity?
How much a method resembles ‘real life’
What is test validity?
The truthfullness of a measure in that it measures what it claims to
What is face validity?
Test appears to measure what is intends to
What is content validity?
Does it cover the full range of symptoms of a construct?
What is construct validity?
The degree to which a test measures the construct/ concept at which it is aimed
What is convergent validity?
The degree to which it correlates with other measurements measuring the same construct
