research methods Flashcards
Experimental method
manipulating the IV to have an effect on the DV
what is levels of the IV?
-testing the effect of the IV using different experimental levels i.e a control condition and an experimental condition
What is operationalising?
-ensuring that both the IV and DV are measurable and clear
what is an aim?
area of psychology that the experimenter is looking into
-developed from theories and similar research
-i.e to investigate whether…
what is a hypothesis?
-testable statement which clearly states the relationship between variables and is developed from past research
-must be operationalised
Directional hypothesis
-predicts a specific direction of the effect between the variables
-i.e there will be an increase/decrease in…
Non-directional hypothesis
-non specific relationship between the variables
-i.e there would be a difference between…
Null hypothesis
-no effect on the variables
Control of variables
-any variable interfering with the IV and DV should be removed or well controlled.
Extraneous variables
- a ‘nuisance’ variable which is not the IV but affects the DV
-do not vary systematically with the IV
-make results harder to detect and should be removed before study.
situational variables
-factors in the environment which impact the study
-i.e weather, time
-extraneous
participant variables
-individual differences between participants which affect the study
-i.e gender, age
-extraneous
Confounding variables
-does change systematically with the IV
-becomes difficult for the researcher to be sure of what impacted the DV
-turns into a second unintended IV
Demand characteristics
-ppt may guess the aim due to cues from the researcher or situation.
-extraneous variable
Social desirability
participants automatically try to respond in ways that make them seem likeable in a study, even if it means misrepresenting how they truly feel.
‘please-U’ effect
-ppt may act in a over-way they think is expected or wanted from the researcher to fulfil hypothesis
‘screw-U’ effect
-ppt may deliberately under-perform to sabotage the results of the study
Investigator effects
-when a researcher influences the outcome of any research they are conducting
conscious or unconscious
-i.e leading question, selection of ppts.
Order effects
when participants’ responses in the conditions are affected by the order of conditions to which they were exposed
Randomisation
-use of chance methods wherever possible to reduce the effect of bias from investigator effects
- minimises impact of confounding/extraneous variables.
Standardisation
all ppts should be subject to the same environment, info and experience
-i.e standardised instructions read to each ppt
-means that non-standardised changes in procedure do not act as extraneous variables
Experimental designs
Independent groups
-different ppts complete different levels of the IV/conditions.
-groups are randomly allocated to prevent bias
Advantages +Disadvantages of Independent groups
-demand characteristics are minimised.
-no order effects
HOWEVER
-extraneous variables i.e differences between ppts due to random allocation may impact results
-requires more ppts so less economical(time/money)
Repeated measures
-same ppts take part in all conditions/levels of the IV.
- produces related data, can compare how ppts did in both conditions
Advantages+ Disadvantages of Repeated measures
-needs less ppts so more economical
- higher validity as ppt variables will not affect results as much
HOWEVER
order effects:
-may create boredom or fatigue(important in skill-based tasks)
-practice effects
-first condition may have an effect on the other one
How can you control the order effects in a repeated measures design
Counterbalancing
- this uses an ABBA format
- Half the ppts complete condition A then B
- other half complete condition B then A
Matched pairs
-pairs of ppts are matched in terms of key variables i.e age
-one member of each pair is placed in two different conditions
-minimises ppt variables but does not eliminate them
-avoids order effects
-time consuming, expensive as may require pre-test
What is reliability?
-how consistent results are, whether research can be repeated with those results
What is validity?
-accurately measuring what you are claiming to measure
Internal validity
-whether the IV changed the DV without influence of other factors.
what affects internal validity?
particapant variables (demand charctertics, personality, age)
- Lack of control (order effects, investigator effects)
- situational variables (temp, room size)
- Researcher Bias (lack objectivity)
-face validity(claim to measure what its measuring)
What is external validity?
can you apply the findings to the public or day to day life (generalisability)
Ecological validity
can generalise to a different place or setting
mundane realism
is the task similar to what we would do in real life
population validity
ability to generalise the findings to the wider population
-affected by androcentric / gynocentric
Historical validity
Can you generalise to a different century, or decade
How would we improve our external validity?
Using field study, natural observations etc
Types of experiments
Lab experiments
-conducted under controlled environment for conditions/lab
strengths+limitations of lab experiments
-high internal validity= control of EVs and CVs mean cause and effect is certain
-high replicability because there is a standardised procedure
HOWEVER
-low external validity=cannot be generalised to un artificial contexts
-give rise to demand characteristics
-lack of mundane realism
-experimenter bias
field experiments
-IV is manipulated in the ppt’s more natural,everyday setting
strengths+limitations of field experiments
-High external validity which means you can generalise it to real life situations
-higher mundane realism
-less mundane realism as people show more naturalistic behaviours
HOWEVER
-loss of control of CVs and EVs —> difficult to establish cause and effect
-possible ethical issues about consent and privacy
natural experiments
-Change in IV has occurred naturally so not be manipulated by researchers
strengths+limitations of natural experiments
- high external validity (changes happened in real life)
- allow research in areas that could not happen due to ethical or cost reasons
HOWEVER
-may occur rarely and reduce research opportunities
-may not be randomly allocated to experimental conditions so other factors may affect the DV
Quasi-experiments
-IV based on an existing difference between ppts and un manipulated
-DV can either be naturally occurring or devised by experimenter
Strengths and limitations of quasi-experiments
-same as lab due to controlled conditions
HOWEVER
-cannot randomly allocate ppts to conditions so may be confounding variables
-other ppt variables may come into play
Population&target population
-large group of individuals that a researcher is interested in studying
-subset of general populations that research is specifically about
sample
-ppts representative of the target population so results can be generalised
Random sample
each person in target population has an equal chance of being chosen
1. have a list of the target population
2. enter names into hat, computer system
3. Place names into either conditions until there is an equal number of ppts in each condition(reference the number according to target population in the question)
Advantages+disadvantages of random sample
-avoids researcher bias, as researcher cannot choose ppts from sample
HOWEVER
-could proudce an underepresentative sample
- can be time consuming to get full list of target population
systematic sample
-ppts chosen from list of target population and every nth ppts chosen to from sample
-process is repeated until sample required is chosen
-method is subjective
advantages+disadvantages of systemic sample
-avoids researcher bias because researcher can’t choose who they want in sample
– quick method of chosing sample
HOWEVER
-could result in unrepresentative sample
-time consuming and ppts may refuse to take part
- if target population is too large full list difficult to obtain
opportunity sample
-researcher directly asks members of the target audience if they are avaliable
-likley to be someone researcher has easy access to or familiar with
advantages+disadvantages of opportunity sample
-convenient as there is no need to divide the population into different strata
-less costly
HOWEVER
-researcher bias as researcher asks who they want to take part in the study, may choose those who they prefer
- unlikley to be representative (for example research conducted in Unis is likley to have young undergrad students so cannot be generalised
volunteer sample
-ppts offer to take part study after seeing an ad in a newspaper or online
advantages+disadvantages of volunteer sample
-easy, minimal input from researcher
-less time consuming
-ppt ends up more engaged and willing to participate
HOWEVER
-may not be generalisable to target population becuase of volunteer bias (more likely attract a certain profile i.e more curious and helpful)
BPS CODE OF CONDUCT (6 points)
Informed consent: ppts must be told about research before taking part and their right to withdraw
Deception: deliberately misleading or withholding info from ppts at any stage of research.
protection from harm: ppts should not be exposed to psychological/physical harm more than expected in day to day life
Confidentiality: right to have all personal info protected under the data protection act away from publications
privacy: right to control info about themselves.
how we deal with informed consent issue
Prior general consent: ppts can sign a consent form
presumptive consent details explained to a similar representative group and ask if they would agree to conditions
retrospective consent: ppts asked to give consent after the study
how is protection from harm and deception dealt with?
a debrief where:
1) you thank them for taking part
2)a full explanation of the study is offered(aim, hypothesis) and further psychological support
3) right to confidentiality and right to withdraw info is given
how do we deal with confidentiality?
-try and maintain anonymity through giving ppts numbers or using initials in a case study.
-remind ppts before and after study that data will be protected
psychological realism
thought processes that participants use in the study may be quite common in the real world
costs and benefits of ethics issues
:( harmful for ppts, time consuming, invasion of privacy, can be upsetting, lead to harmful conclusions
:) ppts get paid for their time, researchers can develop theories from it
Explain the role of ethics committees
-researcher must write a proposal outlining how the researcher will meet ethical guidelines+ justification for any breaches
-all research must be approved by the committee
-made up of lay people+independent staff members
-if a researcher behaves unethically, they are barred from practicing as a psychologist
What is the ‘measures of central tendency’?
‘averages’ which give us information about the most typical values in a set of data
What are descriptive statistics?
the use of graphs, tables and summary statistics to identify trends and analyse sets of data
The mean(the average)
-most sensitive of the measures of central tendency as it includes all of the scores/values in the data set within the calculation= most representative
-harder to calculate than other measures
-cannot be used for categorised data
-can be affected by extreme values
What is categorised data?
can be divided into different categories but cannot be ordered/measured
can be nominal i.e hair colour, binary i.e has a pet or doesn’t and ordinal i.e ranking things 1st,2nd and 3rd
The median(middle value when scores are ordered highest to lowest)
-easily identified (just find the middle of the 2 medians in an even number of values)
-easier to calculate than the mean
-unaffected by extremes
-less representatives as it doesn’t not use all scores and ignores the actual highest/lowest values
The mode(most frequent score)
-very easy to calculate
-data is often multi-modal so doesn’t show much
-unrepresentative as it doesn’t use all scores
-sometimes the only method that can be used
What are measures of dispersion?
based on the spread of scores: how far they vary from one another
What is range?
-taking the lowest score from the highest and (usually) +1
-adding 1 that allows for the fact that raw scores are usually rounded when recorded
Evaluation of range
-shows the overall spread of data in a set
-easy to calculate
-may not be representative of the data if there are extreme values at the top/bottom of the dataset