Research issues

Question 1

what are the ‘unwanted factors’ in an experiment

Answer 1

• extraneous variables
• confounding variables
• demand characteristics
• investigator effects

Question 2

what are extraneous variables

Answer 2

• any variable other than the IV that can affect the DV if it is not controlled
• EVs are nuisance variables that interfere with the IV

Question 3

what are confounding variables

Answer 3

• a type of EV but is unpredictable

- occurs by surprise and cannot be controlled

Question 4

what are demand characteristics

Answer 4

• ppts will always try to figure out the purpose of an investigator which could make results unreliable
• clues given by the researcher (unintentionally) that enable ppts to guess the aim of the experiment

Question 5

what are investigator effects

Answer 5

• any effect of the investigators behaviour on the DV

- can cause demand characteristics or happen as a result of demand characteristics

Question 6

how can unwanted factors be overcome

Answer 6

randomisation and standardisation

Question 7

what is randomisation

Answer 7

• using chance methods
• reduces demand characteristics and investigator effects (unconscious bias)
• manipulating IV in different orders

Question 8

what is standardisation

Answer 8

• all ppts subject to same experience
• reduces EV
• all elements of experiment are the same