controlling extraneous variables Flashcards
research methods
What is an extraneous variable?
Any variable that is not the IV which produces a change in the DV this lowers the validity of the results
What are the types of situational variables?
Variables connected with the research situation used in the investiagtion e.g. temperature, instructions given, time of day, lighting and materials
How do you control situational variables?
Controlled through standardisation ensuring the only thing that differs between two conditions is the IV
One way this can be achieved is by using standardised instructions, materials and procedures. So every participant has the same set
What are the types of participant variables?
Variables connected with the research participants e.g. age, intelligence, gender, personality
How do you control participant variables?
Controlled through experimental designs e.g. matched pairs or random allocation
Counterbalancing is used if a repeated measures design is used to stop practise or fatigue effects