Control of Variables

Question 1

explain extraneous variables?

Answer 1

• the only thing that should affect the DV is the IV
• unwanted variables that may affect the DV or IV are extraneous variables
• they do not vary systematically with the IV
• easy to control, just make it harder to detect results
• only effects one variation eg. light in a lab
• worse to have because only effects one IV

Question 2

explain confounding variables?

Answer 2

• unwanted variables that may affect the DV or IV
• change systematically with the IV (it’s constant)
• harder to control
• not outside changes but inside

Question 3

explain demand characteristics?

Answer 3

• participants may try to work out how they should behave in an experimental situation
• and act in a way they believe is expected to please experimenter or under perform to sabotage results
• please u/screw u effect

Question 4

explain investigator effects?

Answer 4

• investigator may unknowingly through unconscious behaviour encourage a greater level of the DV from pp’s
• eg. smiling when a specific behaviour is performed

Question 5

explain randomisation?

Answer 5

• investigator can minimise the effects of extraneous and confounding variables
• can also control investigator effects
• refers to using chance wherever possible in the investigation

Question 6

explain standardisation?

Answer 6

• all pp’s should be subject to the same environment

- so this happens standardised instructions are read to each pp.

Question 7

explain the difference between confounding and extraneous variables

Answer 7

• confounded= shocked= everything is wrong and effects whole experiment, HARDER TO CONTROL
• extraneous- outside influence eg. lights too dark so no one can see the board for one group but not the other,