research methods Flashcards
what is an aim
General statement that sets out what the researcher wants to investigate.
I.e to investigate wether music genre has an effect on psychology ability
What is an independent variable?
Variable that is manipulated by the researcher or changed in order to see the effects on the dependent variable.
What is a dependent variable?
Variable that is being measured as a consequence to the manipulation of the independent variable.
What is an extraneous variable?
Variable other then the dependent variable that may affect the dependent variable if not controlled. May affect both conditions.
What is a confounding variable
Variable other then the dependent variable that may have affected the dependent variable. Only affects one condition. Identified after the experiment.
Hypothesis writing
There will be a significant increase/decrease/difference in the DV when IV1 compared to IV2
What is operationalisation?
Making variables stated in the aim measurable so they can be precisely tested.
Why do we operationalise the DV
Makes it easier to replicate because it means you can standardise the procedures. This makes it more specific, more objective and thus increases validity.
Why do we need null and alternate hypothesis?
Null hyp= no difference. We need both so that the researcher can accept one and reject the other.
What is the difference between directional and non directional hypothesis?
Directional hypothesis predicts the direction of change( increase/ decrease) whereas non- directional hypothesis doesn’t predict the direction of change- simply states there will be a difference. However does not predict wether there will be an increase or decrease.
When should we use directional and non directional hypothesis?
Directional, use when previous research suggests direction
Non- directional it has not much other research into this specifically. Also use when there is a contradictory previous research.
what is an experiment
it is a scientific investigation of behaviour which involves the manipulation of the IV to observe the effect on the DV.
what are the four types of experiments
Lab, Quasi, Field and Natural
labrotory experiments
Iv is manipulated by the researcher. takes place in a controlled enviornment (artificial ) allows for control over extrenious variables.
STRENGTHS:
- high control over extrrenious variables by controllling EVs we can be confident of the IV Dv link and can establish a strong cause and effect relaionship between the IV and the DV
- controlled nature of the experiment allows for standardised procedure by keeping the fators the same thus we can replicate the study to test for reliability
WEAKNESSES:
- high levels of control= artificial setting
behaviour does not represent real life behaviour giving the research low ecological validity
-participants are aware they are being experimented on so may change their behaviour to suit their aim(demand characteristics). Please you vs screw you effect (sabotage by acting in the opposite from expectations. )
field experiments
IV is manipulated by the researcher, however experiment takes place in a natural environment.There is some control over extraneous variables, more control then a natural experiment however less control then a lab experiment. One example of one is conducting an experiment in a subway- whether the public would help someone who falls over.
STRENGTHS
natural environment findings will represent behaviour that will occur in real life settings so it has high ecological validity.
Ppts less likely to know they are being studied- therefore, unlikely to guess the aim - act more naturally decreasing Demand characteristics.
WEAKNESSES
lower degree of control over extraneous variables cant be confident that the IV caused the DV lowering internal validity and thus weakens the cause and effect relationship
low levels of control also mean difficult to replicate as we cannot standardise or check for consistency therefore it has low reliability
Natural experiments
IV is naturally occuring cannot be manipulated by the researcher, they just take advantage of pre-existing variables
takes place in a natural environment with limited to no control over the extraneous variables.
STRENGTH
takes place in a natural environment- behaviour will be representative of Real life behaviour- increasing in ecological validity.
ppts less likely to know they are being studied= no change in behaviour = low demand characteristics.
Weaknesses
difficult to replicate as it is unlikely that certain situations will; occur in the same way- if we cannot repeat the experiment to check for consistency in results =reducing reliability.
no control over extraneous variables- cant be aware IV alone caused the DV weakening the cause and effect relationship.
Quasi Experiments
IV is a naturally occuring difference between the participants- pre exisiting within the participants
Can take place in controlled conditions (artificial), i.e de[ression vs OCD, cannot make any ppt have depression or OCD
STRENGTHS
allows researchers to study variables that would otherwise be unethical to study, such as depression and attachment styles
highly controlled situation= increased cause and effect relationship
WEAKNESSES
ppts cannot be randomly allocated to conditions
there will be other confounding variables that may have an affect on the DV- researcher has no control over. These variables are known as ppt variables, cannot control ppt variables as we cannot use random allocation in a quasi exp due to them already being split due to characteristics, unable to allocate them into those conditions/ different conditions.
what is reliability
the extent to which the method of measurment can produce consistant findings. If it produces consistent findings then it is reliable
how do you test reliability?
replicate the research to check for similar results using test retest method- =do the test again to see whether it produces the same results if the results are the same/ similar it is reliable.
How do you improve reliability
keep procedure standardised- same time, same measurements, same test(depending on what the study actually is) same instructions.
what is validity- internal?
the extent to which the test measures what it intends to measure- IV causes DV and the extraneous variables have been controlled
what is external validity
what goes on outside the study- can it be applied t the real world, different groups of people/ situations/ time periods?
types of experimental designs
repeated measures, independent groups and matched pairs
independent groups
diff ppts take part in diff conditions- only exposed to one condition Researcher divides the total ppt into as many equal groups as there are conditions.
STRENGTHS
no order effects, ppt only take part in one condition. Increase validity as IV affects DV rather than rather than boredom or practice.
Less demand characteristics they only take part in one condition so less opportunity to guess the aims of the experiment.
weaknesses
there are individual differences because ppt take part in different conditions, thus results may be as a result of individual differences rather then because of manipulation of IV. More ppts are required.