Control Of Variables

Question 1

What are extraneous variables

Answer 1

All variables which are not the IV which could/may affect the results of the experiment. These must be identified at the start of the study to reduce their influence

Question 2

What are confounding variables

Answer 2

Any variable other than the IV that may have affected the DV meaning we cannot be sure what truly caused change in DV. These vary systematically with the IV

Question 3

What are demand characteristics

Answer 3

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

Question 4

What are investigator effects

Answer 4

Any effect of the investigators behaviour on the research outcome (DV), includes design of the study and selection and interaction with pps during research process

Question 5

What is randomisation

Answer 5

The use of chance in order to control the effects of bias when designing materials and deciding the order of conditions

Question 6

What is standardisation

Answer 6

Using exactly the same formalised procedures and instructions for all participants in a research study

Question 7

What is participant reactivity

Answer 7

When behaviours and reactions are impacted by participants knowledge that they are part of a study

Question 8

Two types of EVs

Answer 8

Participant variables and situational variables

Question 9

What is screening

Answer 9

Testing everyone before study to make sure they are suitable participants and are representative of target population. Then remove anomalous participants from the sample.

Question 10

Possible examples of demand characteristics

Answer 10

-pps may try to please researcher by giving the ‘right’ results
-may try to annoy the researcher by giving the ‘wrong’ results
-may act unnaturally due to social desirability bias

Question 11

What is social desirability bias

Answer 11

When participants behave unnaturally to reflect how they would like to be seen

Question 12

Ways to control EVs

Answer 12

-screening of participants
-make all pps do test in same place at same time
-script all interactions between researchers and participants
-observe participants covertly (CCTV, one way mirror)
-double blind procedure

Question 13

What is a single blind procedure

Answer 13

When participants are not told the true aims of the study

Question 14

What is a double blind procedure

Answer 14

When neither participants nor researcher carrying out the investigation know the aims of the study