Control of Variables

Question 1

Why do you control extraneous variables?

Answer 1

To show experiments result are cause and effect

Question 2

What is an extraneous variable?

Answer 2

• All variables (which are not the IV)

- Could effect results of investigation

Question 3

What are four types of extraneous variables?

Answer 3

• Situational variables
• Participant variables
• Investigator effects
• Demand characteristics

Question 4

What is confounding variables?

Answer 4

• Systematically change with IV

- Cannot show if change in DV is caused by IV or confounding variables

Question 5

What is demand characteristics?

Answer 5

Any cue from the researcher or research situation that may reveal the aim of the study

Question 6

What is investigator effects?

Answer 6

Effect of investigator’s behaviour on the outcome of the

Question 7

What is randomisation?

Answer 7

The use of chance when designing investigations to control for the effects of bias

Question 8

What is standardisation?

Answer 8

Use exactly the same formalised procedure for all participant in a research study

Question 9

What is a control group?

Answer 9

• Setting up a comparison

- Help establish causation

Question 10

What is inter-rater reliability?

Answer 10

Independent raters rate same behaviour as researcher – check for agreement

Question 11

What is situation variables?

Answer 11

Aspects of the environment that might affect the participant’s behaviour

Question 12

How to reduce situation variables?

Answer 12

Standardised procedures

Question 13

What are examples of situation variables?

Answer 13

e.g. noise, temperature, lighting conditions

Question 14

What is participant variables?

Answer 14

Each participant varies from the other, and how this could affect the results

Question 15

What are examples of participant variables?

Answer 15

e.g. mood, intelligence, anxiety, nerves, concentration

Question 16

What can be done to reduce participant variables?

Answer 16

• Random allocation

- Order effect

Question 17

What can effect participant variables?

Answer 17

Experimental design

Question 18

What is social desirability bias?

Answer 18

• Changing behaviour to act in line with what is considered socially acceptable
• Not be representative of participants