The flashcards below were created by user
on FreezingBlue Flashcards.
What methods can be used to control secondary variables?
- Elimination - completely remove the variable
- Constancy - ensure variable is constant for all participants
- Convert variable to an IV
- Randomisation - smear unknown/uncontrollable variables across sample
- Statistical adjustment - use change scores (pre and post), or ANCOVA
List 10 sources of experimental invalididty
- Retroactive history - something that changes during course of experiment
- Regression to the mean - extreme scores on a pre-test that move closer to the mean post-test
- Repeated testing - learning or sensitisation effects
- Proactive history - subject variables
- Interaction effects - effects of earlier treatment still present during subsequent treatments
- Loss of participants - of concern if due to treatment
- Maturation - important for studies that run over long periods of time
- Experimenter bias
- Errors in measurement of DV
- Errors due to inappropriate
What are possible types of problems related to generalisation?
- Subjects - how representative of the general population are they?
- Settings - laboratory vs field/natural setting
- Experimenter - influence on DV due to interpersonal skills and mode of interaction
- DV - validity of operationalisation, measures
What is the p-value?
Probability that differences between means is due to chance alone if the null hypothesis is true
What is the relationship between F and t when there are only 2 groups?
F = t2