Control Flashcards
What do researchers do to extraneous variables?
Control them.
What are 4 ways that EVs can be controlled?
Random allocation
Randomisation
Standardisation
Counterbalancing
What are extraneous variables?
Any variable other than the IV that might affect the DV and thus affect the
results.
What is a control variable?
A variable that is kept constant so that it cannot affect the results.
What are the 2 types of control variables?
Extraneous
Confounding
What is a confounding variable?
A variable that varies systematically depending on the IV.
It’s an EV that can’t be controlled.
Give examples of extraneous and confounding variables.
Extraneous =
Temperature, noise level…etc.
Confounding =
Age, gender, smoking, illness
What are the types of extraneous variables?
Participant
Situational
What are situational variables? How are they controlled?
Variables related to situation and environment.
E.G. temperature, time of day, lighting…etc.
Controlled though standardisation.
E.G. making sure that the temperature is same for both groups, the time of day is the same, etc.
What are participant variables? How are they controlled?
Variables related to participants & characteristics.
E.G. age, intelligence, gender, etc.
Controlled using matched pairs design, or randomly allocating participants to conditions, which helps to reduce bias.
What is random allocation?
Allocating pps to different levels / conditions of IV using chance.
Less likely that pps with similar characteristics end up in same group - randomly distributed.
Decreases chance of participant variables affecting DV.
What is counterbalancing?
Method used to reduce order effects in repeated measures.
One half of pps completing 2 conditions in 1 order and other half complete conditions in opposite order.
Order effects balanced out.
Group 1 do A, then B.
Group 2 do B, then A.
What is randomisation?
When tasks/trials are presented in random order to avoid any bias that the order of the trials might cause.
What is standardisation?
When procedures used in research are kept the same.
Any changes in data is linked to the IV.
Research can be replicated easily.
