control of variables

Question 1

what are extraneous variables (2)

Answer 1

-variables other than the IV which affects the DV if it isn’t well-controlled
eg. age of participants, lab lighting
-they make it harder to detect a result- they don’t vary systematically with the IV

Question 2

what are confounding variables (3)

Answer 2

-variables other than the IV which affects the DV if it isn’t well-controlled
-changes systematically with the IV
-becomes difficult to be sure of the origin of the impact of the DV
eg. memory test done at different times of the day- should be done tat the same time

Question 3

what are demand characteristics (3)

Answer 3

-a cue from researcher/situation which may allow participants to guess the aim of the study
-causes behaviour to change from how they would usually act- participant reactivity
-please you and screw you effect- affects validity of results

Question 4

what are investigator effects (2)

Answer 4

-effects of the researchers behaviour on the DV
-eg. design of study, selection of participants, interactions with participants

Question 5

what is randomisation (3)

Answer 5

using chance to reduce the effects of bias from investigator effects
-minimises effects of extraneous/confounding variables
eg.memory test for recalliing order of words on list should be randomly generated

Question 6

what is standardisation (2)

Answer 6

-using the exact same procedures, environment and instructions for all participants
-allows the elimination of non standardised instructions as extraneous variables

Question 7

what is single blind procedure (3)

Answer 7

-researches dont tell participants the aims/conditions
-used to ensure participants dont bias the results
-avoids demand characteristics

Question 8

what is double blind procedure (2)

Answer 8

-neither participants nor researcher knows the aims
-prevents bias in results due to demand characteristics or placebo effect

Question 9

what are control groups (2)

Answer 9

-used to set a baseline to compare results from the experimental condition
-if theres a significant change in experimental condition compared to control group we can be more sure it was the effect of the IV

Question 10

what are pilot studies

Answer 10

small scale versions of a study done before the real study to identify potential problems so they can be dealt with