extraneous and confounding variables

Question 1

Extraneous variable

Answer 1

• unwanted extra variables
• other than IV
• that could have an effect on DV
• lower internal validity of the study

can be asked by EV should be controlled

Question 2

Three main causes of extraneous variables

Answer 2

1. situational factors
2. participant variables
3. experimenter variables

Question 3

Situational factors

Answer 3

• things to do environment when research carried out
• e.g. task difficulty, temp, standardised instructions

Question 4

Participant variables

Answer 4

• things to do with ppts
• e.g. age, gender, IQ
• only used for independent groups design

Question 5

Experimenter variables

Answer 5

• things to do with researcher
• e.g. investigator effects

Question 6

Confounding variables

Answer 6

• when an extraneous variable is not controlled for
• does affect DV
• so becomes confoudning