Control of Variables

Question 1

What are the six ways to control variables?

Answer 1

1) Extraneous variables
2) Confounding variables
3) Demand characteristics
4) Investigator effects
5) Randomisation
6) Standardisation

Question 2

How and when are extraneous variables identified?

Answer 2

Extraneous variables tend to be identified at the start of a study, which then allows the researcher to take steps to minimise their influence

Question 3

What are extraneous variables?

Answer 3

Other variables that might potentially interfere with the IV should be controlled or removed

Question 4

What term is used to describe variables that are straightforward to control?

Answer 4

Nuisance variables

Question 5

What are “nuisance variables”?

Answer 5

Nuisance variables are variables that are straightforward to control and do not vary systematically with the IV

Question 6

What is an extraneous variable that involves participants?

Answer 6

Participant reactivity

Question 6

What are confounding variables?

Answer 6

Any variable that may have affected the DV so we cannot be sure of the true source of changes to the DV

Question 7

What is participant reactivity?

Answer 7

Participant reactivity is when the participants take their time to try and make sense of the new situation

Question 8

What are investigator effects?

Answer 8

Any effect of the investigator’s behaviour on the research outcome

Question 8

What are two ways that participants may act to either aid or sabotage the research?

What is the name given to describe a participant aiding the research or sabotaging the research?

Answer 8

Participants may act in way that they think is expected or over - perform to please the experimenter (this is called the ‘please-U effect)

They may also deliberately under - perform to sabotage the results of the study (this is called the ‘screw-U effect)

Question 9

What are demand characteristics?

Answer 9

Any cue from the researcher or from the research situation that may be interpreted by participants as revealing the purpose of the investigation. This may lead to a participant changing their behaviour within the research situation

Question 10

What can participant reactivity lead to?

Answer 10

Participant reactivity can lead to investigator effects

Question 11

What is randomisation?

Answer 11

Randomisation refers to the use of chance wherever possible to reduce the researcher’s influence on the design of the investigation. An attempt to control investigator effects

Question 12

What is standardisation?

Answer 12

Standardisation is when the exact same formal procedures and instructions are used for all participants in a research study