Extraneous and confounding variables Flashcards
Extraneous variable
Any other variable other than the IV that causes a change in the results and therefore has an unwanted effect on the experiment
Example: Participant mood, personality, motivation, memory
Confounding variable
when an extraneous variable has a confounding effect on the results it is known as a uncontrolled variable that has a definite unwanted effect on the experiment. (unwanted variable)
Artificiality
the unnatural environment in which an experiment is conducted -can produce demand characteristics
Demand characteristics
when participants knowledge about the aims of the study impact on their behaviour. Also if participants behaving in a certain way that they believe is a desirable to the experimenter.
Standardised procedures
to keep consistent each test and its procedure making sure all conditions are the same each time
Order effects
occurs when the performance, as measured by the DV, is influenced by the specific order in which the conditions, treatments or tasks are presented. (mainly in repeated measures design). Can be eliminated by counterbalancing
Carry-over effects
are the influence that a particular treatment or task has on performance in a subsequent treatment or task that follows it
Boredom effects
The repetition of the same task, or lack in concentration due to the simple nature of the task, its duration and lack of concentration of the participants
Experimenter effects
occurs when there is a change in a participant’s response due to the researcher’s expectations, biases or actions, rather than the effect of the independent variable. Can be eliminated through standardised prodecedures and double-blind procedure
Placebo effect
refers to the improvement in health or wellbeing due to an individual’s belief that the treatment given to them will be effective. Can be eliminated with a single-blind procedure
