validity; confounding variables

Question 1

what is a confounding variable?

Answer 1

• a variable that is not the independent variable (IV) under study but which varies systematically with the IV. Changes in the dependent variable may be due to the confounding variable rather than the IV, and therefore the outcome is meaningless. to “confound’ means to cause confusion.

Question 2

what is control?

Answer 2

• refers tot he extent to which any variable is held constant or regulated by a researcher.

Question 3

what is external validity?

Answer 3

• the degree to which a research finding can be generalised; to other settings (ecological validty); to other groups of people (population validity)’ over time (historical validity).
• External validity is the validity of generalized (causal) inferences in scientific research, usually based on experiments as experimental validity. In other words, it is the extent to which the results of a study can be generalized to other situations and to other people.

Question 4

What are extraneous variables?

Answer 4

• do not vary systematically with the IV and therefore do not act as an alternative IV but may have an effect on the dependent variable.
• they are nuisance variables that muddy waters and make it more difficult to detect a significant effect.

Question 5

what is internal validity?

Answer 5

• the degree to which an observed effect was due to the experimental manipulation rather than other factors such as confounding variables.

Question 6

what is mundane realism?

Answer 6

• refers to how a study mirrors the real world. the research environment is realistic to the degree to which experiences encountered in the research environment will occur in the real world.

Question 7

What is validity?

Answer 7

• refers to whether an observed effect is a genuine one.

Question 8

give an example of a confounding variable?

Answer 8

• if an experiment where the aim was to see if participants could do their homework effectively while in front of the tv.
• IV was whether the tv was on or not
• DV was the participants score on the memory test.
• TV would be the distraction and, the TV off group should do better on the test.
• but consider the TV off group did the test in the morning and the other group did their test in the afternoon.
• the time of day could be considered a confounding variable.

Question 9

Give an example of an extraneous variable?

Answer 9

• some students will have better memories than others. it is unlikely that all people with better memories would end up in the ‘TV off’ group. if they did, this would act as a confounding