Research methods: experimental Flashcards
IV definition
variable that is manipulated by the researcher to see if it has an effect on the DV
DV. definition
variable that is measured to see the effect of the IV
operationalising definition
to be clear and specific when defining the IV and DV to make it easier to measure
what is the aim of research
-general statement of what the researcher intends to investigate
-purpose of the study
what is the hypothesis of the research
specific, testable statement in which the researcher predicts what will happen between the variables
directional hypothesis definition
the researcher predicts the direction that the results will go in
another name for a directional hypotheses
one tailed hypothesis
writing frame of a directional hypothesis
There will be a significantly higher/faster/more (operationalised DV) when participants (one condition of IV) compared to when participants (other condition of the IV)
null hypothesis definition
- IV has no effect on the DV
-results were due to chance
null hypothesis writing frame
there will be no significant difference in (operationalised DV) when (operationalised IV) compared to (operationalised IV)
Extraneous variable definition
-unwanted extra variables other than the IV that could have had an effect on the DV
-lowers the internal validity of the study
confounding variables definition
when an extraneous variable is not controlled for and it does affect the DV
lab method AO1
-highly controlled environment
researcher manipulates the IV
-to see the effect on the DV
lab methods strengths
High level of control over extraneous variables therefore cause and effect can be established between the IV and the DV which increases the internal validity of the research.
High in reliability as the experiment can be easily repeated in the same conditions to check for consistent results.
lab methods limitations
Lacks Ecological validity as it’s carried out in an artificial environment therefore it is difficult to generalise the findings beyond the setting of the study, lowering the external validity.
Can encourage demand characteristics, where the Ppt’s change their natural behaviour based on clues given off by the researcher this could lead to ppts choosing to either help/hinder the researcher, reducing the internal validity.
field method AO1
natural environment
researcher manipulates the IV and records the effect on DV
field method strength
Less prone to demand characteristics as people might not know they are being watched so they are less likely to guess clues given off by the researcher and change their natural behaviour in order to help/hinder the research Therefore increasing the internal validity.
High ecological validity as it is based in a real life setting therefore it is easier to generalise the findings beyond the setting of the study to other similar settings increasing the external validity.
field method weakness
Low in reliability as the environment is real so it is difficult to repeat with exactly the same conditions to check for consistent results.
This could create an ethical issue of lack of informed consent as people may not be aware they are being studied on so wouldn’t have given their consent. If they become aware they may become upset and wish to withdraw their data from the research.
natural method AO1
-naturally occurring IV
-changed even if the experimenter not interested
-could happen in a lab or a field
natural method strength
Natural experiments provide opportunities for research that may not otherwise be undertaken for practical/ethical reasons. For example, Rutter’s study on Romanian orphans would have been unethical to manipulate unless the institutionalisation (IV) had not occurred naturally. Therefore, natural experiments contribute to a greater psychological understanding of behaviour.
High ecological validity as natural experiments are often based in a real life setting therefore it is easier to generalise the findings beyond the setting of the study to other similar settings increasing the external validity.
natural method limitations
Naturally occurring event may only happen very rarely which limits opportunities for research, unlike lab experiments where IVs can be manipulated by the researcher any time. Suggesting other types of experiment may be more convenient for research than natural experiments.
Low control over extraneous variables as natural experiments usually take place in a natural environment. Therefore it is difficult to establish cause and effect between the IV and the DV lowering the internal validity of the study.
quasi method AO1
-existing difference between people
-which the researcher has not manipulated
-records the effect on DV
eg. age or gender
quasi method strength
quasi method strength
quasi method limitations
Sample bias as the sample being studied may have unique characteristics, which may mean that it is difficult to generalise to the target population decreasing the external validity of the study.