experiments Flashcards
define independent variable
what the researcher wants to compare/manipulate/change
define dependent variable
what the researcher measures
define extraneous variables
factors which may influence your DV and aren’t your IV, but that can be controlled to minimise their effects
define confounding variables
factors which may influence your DV and aren’t your IV but are outside your control
what is a laboratory experiment?
conducted in a controlled/artificial environment with a manipulated IV
what are the strengths of a lab experiment?
- high level of control, increasing replicability
- easier to establish causal relationship as we are manipulating the IV
- most scientific type of experiment and often uses objective equipment
what are the weaknesses of lab experiments?
- increased chance of demand characteristics
- low in ecological validity due to high level of control
what is a field experiment?
- manipulated IV
- environment is where you would expect to see that behaviour occur or in a natural environment
what are the strengths and weaknesses of field experiments?
STRENGTHS:
- higher ecological validity
- easier to establish causal relationship as we are manipulating the IV
WEAKNESSES:
- reduced level of control
- lower replicability
- less scientific due to lower levels of control
what is a quasi experiment?
- naturally occuring IV
- can be conducted in either controlled or naturally occuring environments
what are the strengths and weaknesses of quasi experiments?
STRENGTHS:
- allows us to investigate variables it would be impossible/unethical to investigate otherwise
- can be carried out in a lab or in the field so may have the same strengths as those types
WEAKNESSES:
- difficult to establish causal relationships because the IV is not controlled/manipulated
- sampling bias as the researchers cannot control who takes part in each condition
what is an independent measures design?
where different participants take part in each condition
what are the strengths and weaknesses of an independent measures design?
STRENGTHS:
- no chance of order effects
- reduced risk of demand characteristics (les likely to guess aim)
WEAKNESSES:
- any difference between conditions may be down to individual differences
- need to recruit a larger number of participants
what is a repeated measures design?
the same participants take part in each condition
what are the strengths and weaknesses of a repeated measures design?
STRENGTHS:
- only have to recruit half as many participants
- no individual differences (using the same people)
WEAKNESSES:
- possible order effects
- higher risk of demand characteristics