Controlling variables

Question 1

What is an extraneous variable?

Answer 1

Any variable other than the IV that may have an effect on the DV if not controlled. EV’s do not vary systematically with the IV.

Question 2

What is a confounding variable?

Answer 2

Any variable, other than the IV, that may have affected the DV so we cannot be sure of the true source changes to the DV. They vary systematically with the IV.

Question 3

What are demand characteristics?

Answer 3

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

Question 4

What are investigator effects?

Answer 4

Any effect of the investigator’s behaviour, conscious or unconscious, on the research outcome (DV). This may include everything from the design of the study to the selection or, and interaction with participants during the research process.

Question 5

What is standardisation?

Answer 5

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

Question 6

What is randomisation?

Answer 6

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