Control variables

Extraneous variablesles

The only thing that should influence the dv is the in.Any other variables that might potentially interfere with iv should be controlled or removed.These unwanted variables are called extraneous variables.

Confounding variables

Any other variable other than the I’ve that may have an effect on the dev if it is not controlled.

Demand characteristics

Certain clues may help them interpret what is going on in the study and these clues are the demand characteristics.

Investigator affect

This is any unwanted influence of the investigator on the research outcome. Eg leading questions.

Randomisation

Refers to the use of chance wherever possible to reduce the researcher influence on the design of the investigation

Standardisation

All participants should be subject to the same environment,info and experience.To ensure that this procedure is standardised,in other words there is a list of exactly what will be done in the study.This includes standardised instructions.