Variables and types of bias Flashcards
What is an extraneous variable?
Any variable other than the IV that might affect the DV
What is a confounding variable?
An EV that is important enough to provide an alternative explanation for the effects on the DV
What are the two types of extraneous variables?
- Situational variable
- Participant variable
What is a situational variable?
A feature of the environment that may affect performance
Give an example of a situational variable
The weather
What is a participant variable?
A characteristic of a participant that may affect performance
Give an example of a participant variable
Intelligence
What is meant by experimenter effects?
When an experimentor unconciously affects the results of an experiment
How can an experimentor affect results?
- Bias
- The way they present themselves, e.g body language, tone of voice, posture
How can experimenter effects be controlled?
- Standardised procedures
- Use a double blind procedure
- Groups of experimenters (inter-rater reliability)
What is a double blind procedure?
Where neither the participant nor the experimenter know what condition the participant is in
What is meant by demand characteristics?
Participants may change their natural behaviour in an experiment to please the experimenter or because they have guessed the aims of the study
How can demand characteristics be controlled?
- Deception e.g lying about the aim, distractor questions
- Use a single blind procedure
What is a single blind procedure?
Where the participant doesn’t know what condition of the experiment they’re in however the experimentor does
