unit 4 - research methods Flashcards
theory
a suggested explanation for behaviour
aim
a general statement that explains the purpose of a study
independent variable
the variable that the experimenter is deliberately changing
there are usually two levels of the IV
dependent variable
what is measured by the researcher
the only thing that should affect the DV is a change in the IV
operationalisation
making sure that variables are measurable, clear and precise
testable hypothesis
a clear and precise testable statement
alternative hypothesis
a statement of relationship or difference between variables
null hypothesis
a statement of no relationship or difference between variables
cause and effect
the only thing that should cause a change in the DV is the IV
if the DV does then change, the experimenter has established cause and effect
extraneous variables
unwanted variables that could affect the DV if they are not controlled
standardised instructions
giving the participants exactly the same information about the study to ensure what is said to them doesn’t act as an EV
standardised procedures
researcher used the same method and instructions for all participants in a research study
randomisation
using chance to control for the effects of bias when designing a research study
lab experiment
an experiment conducted in a controlled environment
give four evaluations of lab experiments
STRENGTH - EVs can be controlled which means that cause and effect can be established
STRENGTH - use of standardised procedure ensures replication is possible so it is possible to confirm the validity of results
WEAKNESS - the environment is not like everyday life so behaviour is less normal and results can’t be generalised to the wider world
WEAKNESS - participants may be aware of their being tested to may change their behaviour, making the data invalid
field experiment
an experiment conducted in a natural setting
experimenter manipulated the IV
give four evaluations of field experiments
STRENGTH - often more realistic than lab experiments due to their natural environment which increases the validity of results
STRENGTH - there is some control over EVs as standardised procedures can be used so cause and effect conclusions are more valid
WEAKNESS - researcher may lose control of some EVs because a real life setting makes it more difficult to control them, making it more difficult to show cause and effect
WEAKNESS - there may be ethical issues with people not being aware of their participation so can’t give informed consent
natural experiment
an experiment conducted in a natural or lab setting where the experimenter has no control over the IV
give four evaluations of natural experiments
STRENGTH - usually have high validity because the variables are naturally occurring and relate to everyday life but this isn’t always the case
STRENGTH - the DV is often tested in a lab so EVs can be well controlled because standardised procedures can be followed
WEAKNESS - may be few opportunities for this kind of research as it may focus on natural, and sometimes infrequent, events so the method’s usefulness is reduced
WEAKNESS - there may be a greater amount of EVs that could affect results such as participant variables which can’t be controlled by assigning to groups
independent groups
separate groups of people for each level of the IV
there is usually a control group and an experimental group
give two evaluation points of independent groups design
STRENGTH - order effects are not a problem as participants only do the task once so they won’t benefit from practice
WEAKNESS - there are different participants in each group meaning that participant variables may affect the results and act as an EV, reducing the validity of results
repeated measures
all participants take part in all the conditions
give three evaluation points of repeated measures design
STRENGTH - there are no participants variables as each participant is compared to themselves as opposed to other people, this enhances the validity of results
STRENGTH - fewer participants are needed so repeated measures is less expensive
WEAKNESS - order effects occur when participants are tested twice ; the order of tasks may make a difference which affects the validity of results
this however can be limited using COUNTERBALANCING
matched pairs
participants are tested in terms of variables relevant to the study
participants are then matched and one member of each pair goes in each group
give three evaluation points of matched pairs design
STRENGTH - there are no order effects, enhancing validity
STRENGTH - there are fewer participant variables because those taking part are matched on a variable important to the experiment ; this enhances the validity of the results
WEAKNESS - matching participants takes time and effort and still doesn’t control all participants so may not be worthwhile therefore
target population
the group of people the researcher is studying
sample
a sample of participants chosen from the target population
generalisation
the sample should be representative so we can generalise to the target population
bias
it is difficult to select a group of participants that perfectly reflects the target population
give 4 types of sampling
random
opportunity
systematic
stratified