Variables

Extraneous variables - (nuisance) variables which may affect the DV that are not the IV.

Examples of extraneous variables: Age of participants, Background noise, Differences in memory.

Confounding variables - difference between the conditions of the experiment that is not in the IV and likely to affect the DV.

Examples of confounding variables: If all people in one condition happen to have a better memory than the people in the other condition. If the testing material in one condition is easier than in the other. If there are huge distractions in one condition but not the other.

Participant variables - individual differences between the participants.

Examples of participant variables - Personality, Age, Gender, Motivation, Intelligence, Concentration.

Situational variables - differences in the situation/ way participants are tested.

Examples of situational variables - Background noise, Time of day, Temperature of room, Weather outside.

Demand characteristics - When participants try to work out what’s going on in the experiment and change their behaviour according to what they think the researcher wants/ doesn’t want. This lowers the ecological validity of the study as their behaviour is no longer natural.

Please-you effect - A participant changes their behaviour to suit what they think the researcher wants, to ‘help’ them.

Screw-you effect - A participant changes their behaviour to the opposite of what they think the researcher wants, to ‘screw them over’.

Investigator effects - Any unwanted influence of the investigator on the DV. It is usually unintentional; it may happen because of the way the experiment is carried out or in the way it was designed (which participants were selected etc.).

Standardization - ensuring the procedures used to test the participants are the same for all variables. We want the IV to be the only thing that varies!

Randomization - When the researcher does not choose something themselves and every potential option has an equal chance of happening.

Reliability - refers to the consistency of the results of the research (if it was replicated would it likely produce the same results?)

Validity - Refers to whether something is truely testing what it is intended to test.