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)