A nuisance variable that can be controlled and does not vary systematically with the IV
What is a confounding variable?
A kind of extraneous variable that varies systematically with the IV, so we cannot be sure whether the change in the DV is due to the IV or confounding variable
What are demand characteristics?
Any cue from the researcher that may be interpreted by ppts as revealing the purpose of an investigation, leading to the ppt changing their behaviour
What are investigator effects?
Any effect of the investigator's behaviour on the research outcome e.g. interaction with ppts during investigation
What is randomisation?
The use of chance to control the effects of bias when designing the investigation
What is standardisation?
Using the same formalised procedures and instructions for all ppts in a study