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.
independent groups design AO1
ppts take part in one condition only
each condition has different groups of ppts
independent groups strength
There will be no order effects as ppts only take part in one condition so they will not get bored/fatigued/better at the task or have lasting effects from one condition to the next UNLIKE repeated measures design where ppts take part in all conditions and could have order effects.
Can be used when repeated measures design is inappropriate (e.g. quasi experiments when looking at gender differences) as each condition needs different ppts
independent groups limitations
Individual differences may affect the DV as there are separate groups of ppts in each condition e.g. some ppts could have a better memory which wouldn’t be suitable in a memory study lowering the internal validity UNLIKE repeated measures that uses the same group of individuals in all conditions to reduce the effect of individual differences.
More ppts are needed as two different groups are required for the different conditions UNLIKE repeated measures where you use less ppts as every ppt takes part in all conditions.
repeated measures AO1
all ppts take part in all conditions of the experiment
repeated measured strength
Individual differences between participants in each condition are removed as the same ppts take part in all conditions.Therefore the researcher can be sure any effect to the DV is sue to the IV and not any confounding variables increasing the internal validity of the research UNLIKE IGD will use different ppts in different conditions so individual
differences could affect the DV
Requires fewer participants as the same ppts take part in all conditions UNLIKE in an independent measures design as separate groups are needed for separate conditions.
repeated measures limitation
Order effects may occur when participants take part in more than one experimental condition they may perform worse/better in the second condition due to bored/fatigue/better in the second condition (due to practice), or there may be lasting effects from condition 1 to condition 2 lowering the internal validity UNLIKE independent measures where ppts only take part in one condition so cannot be susceptible to order effects
Increased chances of demand characteristics as participants take part in all conditions. They may pick up on clues given off by the researcher as they spend much more time with them, or from the research situation , and change their natural behaviour to help or hinder the research. Lowering the internal validity UNLIKE IGD where ppts are less likely to pick up on clues as the only take part in one condition of the research
Matched pairs AO1
-ppts are matched on important characteristics in the study
-given them an appropriate test and match two ppts on same score
-each member is randomly allocated across each condition
matched pairs strength
Reduces individual differences between participants as it matches ppts on variables important to the research, such as IQ/age/happiness.Therefore the researcher can be sure the effect on the DV is due to the IV and not any confounding variables UNLIKE IGD where separate ppts are in separate conditions
There will be no order effects as ppts only take part in one condition so they will not get bored/fatigued/better at the task/have lasting effects from one condition to the next UNLIKE repeated measures design where ppts take part in all conditions and could have order effects.
matched pairs limitations
Very time consuming to match up and find similar participants. The psychologists would need a very large pool of people UNLIKE repeated measures design where you use the same ppts in all conditions
Individual differences cannot be fully eliminated. Psychologists match ppts on variables important for the research but are not able to match ppts on all variables. Therefore this could question the validity of the matched-pairs design. UNLIKE RM where each condition will use the same ppts therefore, individual differences will be eliminated.
demand characteristics
-any clues given off within the research
-lead to ppt change natural behaviour
-either help or hinder the research
non-directional hypothesis
the researcher does not predict the direction that they think the results will go in
non-directional hypothesis writing frame
there will be a significant difference in (operationalised DV) between (operationalised IV) compared to (operationalised IV)
why is randomisation used
to control for bias where aspects of the research should be random and not decided by the research to avoid extraneous variables
how is randomisation used
-for things such as: order of conditions or order of ppts
-names on equal sized paper and put in hat
-random computer generator
why is standardisation used
important that all ppts experience the same environment and instructions to avoid extraneous variables
how is standardisation used
using the same formalised instructions and procedures for all ppts in a research
how can independent groups design be improved
random allocation
-put the names of ppt in a random name computer generator
-randomly select the ppts names and place half in condition 1 and the other half in condition 2
how can repeated measures design be improved
-counterbalancing
half the ppts in condition A then condition B
half of the ppts in condition B then condition A
order effects have been balanced
how to control experimental designs
-random allocation
-counterbalancing
what is the target population
group of people who are the focus of the researcher’s interest
what is a sample
a small target group of people taken from the target population to take part in research
-assumed the sample is representative of the target population
what are the types of sampling
random
systematic
stratified
opportunity
volunteer
random sampling ao1
-every person has an equal chance of being selected
-create a complete list of all the target population
-enter names in a random name computer generator
random sampling ao3
-unbiased as everyone in the target population has equal chance of being selected for the study (context) so extraneous variables are equally divided into the groups to increase internal validity
-very time consuming because takes time/difficult to collect names of ppts in study (context) and not all ppts want to take part in study (context)
systematic sampling ao1
system is applies to select ppts
-create a sampling frame ro organise the target pop. eg. alphabetical order
-decide on the system eg. every 5th person
- chose enough ppts for sample
systematic sampling ao3
-avoids researcher bias as researcher has no influence over who is taken part in study (context) as it is objective once the system is established
- the sample may not be representative as not everyone has an equal chance of being picked therefore difficult to generalise to the target pop. (context) = also creating the system and collecting names is time consuming and difficult for the researcher
stratified sampling ao1
makeup of the sample reflects proportions of certain sub-groups in target pop.
-identify the different sub groups that make up a population eg. males and females
calculate how many of each proportion you would need for sample size eg. 70% of 80 people
-no. ppts which make up each proportion are chosen via random sampling
stratified sampling ao3
- most representative as it accurately reflects the makeup of the target population (context) in the correct proportions meaning findings can be generalised to the target pop.
-very time consuming because it takes time working out the proportions of the ppts needed (context) and it’s not guaranteed the ppts would consent to take part
opportunity sample ao1
being there at that moment time eg. going to canteen and ak the first 30 people who come in to ppts
-go somehwere where you will have access to the target pop. ask the first 30 ppts if they want to ppts
opportunity sample ao1
being there at that moment time eg. going to canteen and ak the first 30 people who come in to ppts
-go somehwere where you will have access to the target pop. ask the first 30 ppts if they want to ppts
opportunity sample ao1
being there at that moment time eg. going to canteen and ak the first 30 people who come in to ppts
-go somehwere where you will have access to the target pop. ask the first 30 ppts if they want to ppts
opportunity sample ao3
very quick, easy and less money is required as you choose who is available at the time of your sample (context) unlike random sampling which takes a long time to identify everyone in the target pop and make a list of names
may not be representative of the target pop. those picked by the sample are present in the same place at the same time doing similar things (context) therefore may have similar personalities eg. so may be difficult to generalise to the wider population
volunteer sample ao1
self-selected method where people volunteer themselves as ppts eg. placing an advert
-place an advert where the target pop. will see it and wait for required sample to reply
volunteer sample ao3
very quick,easy and cheap to conduct as all that is required is placed in an advert for the study in a place the target pop. might be (context) and wait for ppts to volunteer; unlike random sampling which takes time to place names into a hat
sample may not be representative as only a certain type pf personality may volunteer (context) therefore difficult to generalise to the target pop.
what is the way to assess reliability
test-retest
process of test-retest
- ppts are given a task to complete (context)
- same ppts are given the same task (context) after a time delay
- strong positive correlation of above +0.8 shows high reliability
definition of reliability
ability to repeat the study to check for consistent results
how to conduct face validity
- independent psychologist in the same field looks at the conditions/behaviour categories
- sees if they measure what they tend to measure
how to conduct face validity
- independent psychologist in the same field looks at the conditions/behaviour categories
- sees if they measure what they tend to measure (context)
- if the researcher says ‘yes’ the research has face validity
how to conduct concurrent validity
- compare the results of the new test (context) with the results from a similar test which already has been established for its validity, using a stats test
- if results from both tests (context) are similar then we can assume the test is valid. The correlation of the two results gained from an appropriate stats test should exceed +0.8
pilot study definition
small scale trial run of research before the real main scale research to identify any problems and amend them
what are the aims of a pilot study
CONTEXT NEEDED
1.Any problems can be identified and amended
2.Check standardised procedures and general design
3. Check the amount of time given to ppts is enough to complete the task
3. For questionnaire/ interview to make sure the questions are clear
4. For observations check coding systems and behaviour categories are understood/operationalised, check
observer/camera in a good position to see behaviours.
5. Extraneous variables can be identified and possibly eliminated ( how to be eliminated )
6. Ask the ppts to discuss their experiences of the experiment post-research debrief
what are the 4 ethical issues
Deception
Informed consent
Protection of participants
Confidentiality
what does deception mean
ppts are not told the true AIM of the study deliberately, to prevent participants from showing demand characteristics
what does informed consent mean
ppts give permission to take part in the study after being informed of the true aims of the research, as well as being given the right to withdraw
what does protection of participants mean
Ppts should be protected psychologically and physically. They must not be placed at more risk than they would be in everyday life
what does confidentiality mean
Ensuring ppts details and data (findings) remain anonymous so they cannot be identified in the research.
how to deal with deception
- debrief: a post-research interview where ppts are told the true aims of the research and full details of the study are given
-ppts should be given the right to withdraw
-ppts must be reminded that their behaviour is typical of the general public
-if they are embarrassed or stresses they should be offered counselling
how to deal with informed consent
-ppts should be given a consent form with the true nature and aims of the study
-child under 16 cannot give their consent
-presumptive consent
-prior informed consent
-parental consent
-if consent wasn’t gained from the ppts then a debrief should be given and ppts give retrospective consent
-ppts may wish to withdraw their data if they do not consent
what are the 3 other ways to gain consent
-presumptive consent
-prior informed consent
-parental consent
what is presumptive consent
gaining consent from a similar set of ppts who won’t actually be doing the study
what is prior informed consent
getting general consent from ppts of things that ‘could’ happen
what is parental consent
when ppts are too young to give consent this is gained from parents
how to deal with protection of ppts
Right to withdraw - ppts should be offered the right to withdraw at any point during or after the research has taken place
Debrief - reassure the ppts that their behaviour is normal - offer counselling to all ppts
how to deal with confidentiality
Anonymity - All personal information should be kept anonymous e.g. initials or fake names
