Control of Variables Flashcards
what is control?
1
refers to the extent to which any variable is held constant or regulated by a researcher
where can the greatest control be achieved?
3
in a laboratory
but the extent to which findings from the laboratory can be generalised to other environments is debatable
some psychologists argue that we can only discover things about behaviour if we uncover cause and effect relationships in highly controlled laboratory experiments
confounding variables
4
variables that aren’t controlled and do affect the results
changes in the DV may be due to the CV rather than the IV, therefore the result is meaningless as the experimenter may not have tested what they intended to test
such as weather, mood of participants, personalities, etc
EXAMPLE = one group of participants may do a task in the morning while the other group does it is the afternoon, time of day may be a confounding variable because people are generally more alert in the morning and drowsier is the afternoon, this might mean that it was the time of day rather than the IV that caused the change in the DV
extraneous variables
4
any variables other than the IV which may have an effect on the DV
may therefore interfere with the results of the experiment, making it more difficult to detect a significant relationship between the IV and DV
can be controlled by the experimenter
e.g. age of participants, time limits for tasks
explain realism
4
some psychologists argue that studies in the natural environment are the only real option for learning about behaviour, especially in terms of how people behave in real life
studies outside the laboratory tend to have higher ecological validity
if the set up of a study is too artificial or contrived then the participants will not act as they normally would in real life
effects how well findings can be generalised to the real world
mundane realism
4
refers to how a study mirrors the real world
the research environment will be realistic if uses tasks or experiences that occur in the real world
lack of mundane realism means something is not like every day experience, meaning that the results of the study may not be useful in terms of understanding behaviour in the real world
for example, in Loftus and Palmer participants were shown a film of a car accident and asked about the speed of the car, this is not the same as watching a car accident in real life, therefore the study lacks mundane realism because it is not like everyday experience
demand characteristics
2
when a participant guesses the nature of the experiment and changes their behaviour
thus ruining the results
generalisation
7
results being extended beyond the present study by assuming existing trends will continue
the point of realism is to be able to generalise the results beyond the particular research setting and allow us to understand behaviour in everyday life
the extent to which findings can be generalised to every day life is very important in psychological studies
MATERIALS = if the materials used in a study are contrived (such as film clips) then the behaviour observed may lack realism
ENVIRONMENT = if the environment in which a study is conducted is contrived, especially if the participants are aware they’re being studied, their behaviour may lack realism
finding from a study may still be difficult to generalise, even if the environment and material are natural and have high realism — due to the sample of participants, time it was conducted, etc
for example = if all the participants in a study are American university students, it may not be reasonable to generalise the findings to the behaviours of all people because Americans and students have unique characteristics that may set them apart in someway from other people
validity
3
refers to whether an observed effect is a genuine one OR how true or legitimate something is as an explanation of behaviour
the accuracy of the study
2 types; external and internal
internal validity
5
the degree to which an observed effect was due to the experimental manipulation rather than other factors such as confounding and extraneous variables
refers to how well an experiment is carried in order to be accurate
concerned with what goes on inside a study such as….
- whether the IV produced the change in the DV or if the DV was impacted by CV/EV
- whether the researcher tested what they intended to test
- whether the study possessed or lacked mundane realism
to gain high internal validity, researchers must design the research carefully, control confounding and extraneous variables where possible and ensure that they are testing what they’re intending to test
external validity
5
the degree to which a research finding can be generalised…
- to other settings (ecological validity)
- to other groups of people (population validity)
- over time (historical validity) — e.g. may not be appropriate to generalise findings from a study conducted in the 1950s to today because many other factors affect behaviour now
also affected by internal validity as you cannot generalise the results of the study that was low in internal validity because the results have no real meaning for the behaviour in question
the scientific cycle
5
testing... • writing a hypothesis • designing a study to test the hypothesis • collecting data • analysing results • questioning the validity of the study • drawing conclusions
objective, systematic and replicable observation
building, refining or falsifying
development of a scientific theory
REPEAT CYCLE
