Research Issues

Extraneous Variables: Any variable, other than the independent variable, that may affect the dependent variable if it is not controlled. EVs are essentially nuisance variables that do not vary systematically with the IV

Nuisance Variables: Ones that do not vary systematically with the IV but can make it harder to detect a result, such as lighting in a lab or age of the participants.

Confounding Variables: A kind of EV but the key feature is that it varies systematically with the IV. Therefore we can’t tell if any change in the DV is due to the IV or the confounding variable.

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

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

Randomisation: The use of chance methods to control for the effect of bias when designing materials and deciding the order of experimental conditions.

Standardisation: Using exactly the same formalised procedures and instructions for all participants in a research study.