Variables + Control (AO1)

Question 1

Independent Variable

Answer 1

the aspect of the experiment that is manipulated by the researcher: the variable that you change
e.g. paper size

Question 2

Dependent Variable

Answer 2

the variable that is measured by the researcher. the effect on the DV is caused by the IV
e.g. distance plane travelled

Question 3

Control Variable

Answer 3

any other variables/factors a researcher wants to keep constant - these would have an effect on the DV otherwise
e.g. plane folding method

Question 4

Extraneous Variables

Answer 4

any variable, other than the IV that may have an effect on the DV if it’s not controlled
basically nuisance variables that are usually identified at the start of the study + controlled by the researcher
do NOT change systematically w the IV

Question 5

Confounding Variable

Answer 5

any variable, other than the IV that may have an effect on the DV - in such a way that we cannot be sure if the IV has caused the change in the DV
DO change systematically with the IV
e.g. ppl w larger planes were also stronger throwers

Question 6

2 Types of Extraneous Variables

Answer 6

situational
participant

Question 7

What are the 4 common problems

Answer 7

situational variables
participant variables
demand characteristics
investigator effects

Question 8

Situational Variables

Answer 8

aspects of the environment which may change a ppt’s behaviour
e.g. noise, lighting, temp

Question 9

How to Control Situational Variables

Answer 9

Standardisation
- keep the environment the same + standardise procedures by writing specific instructions for researchers to follow

Question 10

Participant Variables

Answer 10

differing individual characteristics that may impact how a ppt responds in an experiment
e.g. age, gender, IQ, tiredness

Question 11

How to Control Participant Variables

Answer 11

Randomisation
- randomly assigning ppts to your experimental groups

Counterbalancing
- half the ppts experience the conditions in one order + the opposite “

Question 12

Demand Characteristics

Answer 12

ppts often try to figure out what is going on in an experiment and will change their behaviour as a result
i.e. the ‘please-you’ / ‘screw-you’ effect

Question 13

How to Control Demand Characteristics

Answer 13

Single-Blind
- ppts are not aware of which condition they are in, often used in placebo trials as well

Question 14

Investigator Effects

Answer 14

researcher may try and coerce ppts into acting a certain way so that they get the results they desire
e.g. leading questions

Question 15

How to Control Investigator Effects

Answer 15

Double-Blind
- neither the ppt or the experimenter knows which experimental condition the ppt is in