Research issues

• Extraneous Variables: Any variable other than the independent variable, that may affect the dependant variable if it isn’t controlled. They do not vary systematically with the IV.
• Confounding variables: A kind of EV but the key feature is that they vary systematically with the IV. Therefore it is hard to say if any change in the DV is due to the IV or not.
• Demand characteristics: Any cue from the researcher or situation that may be interpreted by the participants as revealing the purpose of the investigation. This may lead to a participant changing their behaviour within the research situation.
• Investigator effects: Any affect of the investigator’s behaviour on the research outcome. This can include the design of the study to the selection of and interaction with the participants during the research process.
• Randomisation: The use of chance methods to control for the effects 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.