Research Methods Flashcards
Independant variable
the variable the experiment manipulates/changes.
Dependant variable
the variable you measure.
Extraneous / Confounding variables
the variables the experimenters try to control / keep the same.
extraneous: affects both conditions.
confounding: affects only one condition.
Operationalisation
both IV & DV have to be measurable & you must operationalise.
- to test effects of the IV.
e.g. love can be measured by; time spent, heart rate, questionnaire, body language etc.
Confounding variable
-when additional variable that is not the IV (e.g. temp), corrupts or impacts the original study for one condition.
-this means the experimenter may have tested something else with the influence of the CV.
Extraneous variables
Can be situational or dispositional.
-situational: noise, time of day, lighting etc.
-dispositional/ppt: age, height, IQ, health, gender etc.
Investigator effects
Behaviour of investigator may affect ppts & the DV.
E.g. investigator may be more positive with 1 group.
Acting in a more/less positive way is an alternative IV. (confounding variable).
researcher bias
Order effects
Repeating a test impacting the performance.
Aim
What the researcher is looking into, doesn’t need to point out variables.
E.g. to investigate whether caffeine makes people more talkative.
Hypothesis
Statement which states precisely what the researcher believe to be true about the target population.
- a testable statement.
- must be operationalised (contain measures of the data).
Null hypothesis
States that there will be no effect (if research doesn’t produce results to accept experimental hypothesis).
E.g. there will be no difference in the quantity of nightmares whether they watch a rom-com & horror.
Directional hypothesis
Hypothesis predicts results of the effect of the variables.
Clear difference between 2 conditions.
E.g. people who drink caffeine become more talkative than those who don’t.
Non-directional hypothesis
States that there is a relationship between the variables but doesn’t specify which way it will go.
E.g. people who drink caffeine differ in terms of talkativeness compared to people who don’t.
Experimental method
Involves the manipulation of an IV to measure the effect on the DV. Experiments may be lab, field or quasi.
Reliability
consistency.
When a piece of research can be repeated in order to get the same results.
Validity
accuracy.
If you are measuring what you’re claiming to measure.
Demand characteristics (extraneous)
Ppt acts in a certain way because they know/guessed aim of experiments.
-help-U/please-U effect.
-screw-U effect.
Please-U effect
Act in a way they think is expected & over-perform to try & please the experimenter.
Screw- U effect
Deliberately underperform to sabotage the results of the study.
Ecological validity
-if the surroundings represents natural surroundings.
E.g. lab is unnatural (low ecological validity).
E.g. field is natural (high ecological validity).
Mundane realism
-how realistic the task is to something they would do in their everyday life.
-realistic & unambiguous.
E.g. learning a list of words (lacks mundane realism).
Historical validity
-if the results would be the same across all eras.
-if so, high historical validity, if not, low historical validity.
Population validity
-if the results can be applied to different groups of people.
-high PV would be applicable to multiple people.
Androcentricity & Gynocentricity
Andro: applying results of males to females.
Gyno: applying results of females to males.
Investigator effects
-any cues from investigator that could encourage certain behaviours in the pt.
-may lead to fulfilling of investigators expectations.
-it is unknowing on part of the investigator.
E.g. spending more time with ppts in 1 condition than the other.
Randomisation
Effects of EVs are minimised through this.
-order of things should be randomised.
-random allocation.
-order of tasks randomised.
E.g. names in hat, lollipops sticks.
Standardisation
Easily repeated to achieve the same results meaning it has a high level of control.
Requires standardised instructions.
Experimental designs
-independent group.
-repeated measures.
-matched pairs.
Independent groups design
-When 2 separate groups of people are allocated in 2 different conditions of the experiment.
-This means ppts experience only 1 level of the IV.
-Then performance of 2 groups is compared.
Repeated measures
-All ppts experience both conditions of the experiment.
-They experience both levels of the IV.
Matched pairs
-Ppts are paired together on variables relevant to experiment.
-Ppts with the similar qualities are paired together to attempt to control the confounding variables (ppt variables).
-Then performance of 2 groups is compared.
Strengths & Limitations of Independent groups design
Limitations:
-ppts who occupied the groups have different ppt variables which may reduce validity.
-more time consuming & less economical as more people needed for conditions.
Strengths:
-avoids order effects/practice effects as ppts take part in only 1 condition.
-avoids demand characteristics as ppts are less likely to guess aims.
Strengths & Limitations of Repeated measures
Strengths:
-ppt variables are more controlled as same are used higher validity.
-less time/money consuming.
Limitations:
-order effects need to counterbalance.
-practice effects.
-could guess aim of experiment.
Strengths & Limitations of Matched pairs
Strengths:
-ppt only take part in single condition so order effects and demand characteristics are less of a problem.
-reduces ppt variables.
Limitations:
-time consuming & economical especially if they use a pre-test.
Strengths & Limitations of Lab experiments
Strengths:
-high control so more likely that affect on DV is due to manipulation of IV. easier to establish cause & effect. High internal validity.
-easy to replicate.
Limitations:
-may lack generalisability as lab may be artificial. (Low external validity).
-demand characteristics.
-low mundane realism.
Strengths & Limitations of Field experiments
Strengths:
-higher mundane realism (high external validity).
Limitations:
-lack of control of CVs & EVs. Means cause & effect is more difficult to establish.
-ethical issues. If ppts are unaware they’re being studied they cannot consent.
Natural experiments
-Similar to lab or field as researcher measures effect of IV on DV.
-However, diff as researcher has no control over IV & cannot change it. (Someone or something else causes IV to change).
-E.g. before & after a natural disaster.
Strengths & Limitations of Natural experiments.
Strengths:
-provide opportunities for research (Rutter et al).
-high external validity as they involve study of real world issues.
Limitations:
-rare.
-ppts may not be randomly allocated to experimental conditions.
-may be conducted in a lab - lacks realism & caused demand characteristics.
Quasi experiments
-Have an IV that’s based on an existing difference between people.
-Not manipulated and can’t be changed.
-E.g. experimenting phobia and non phobia.
Like a natural experiment, DV could be naturally occurring or devised.
Strengths & Limitations of Quasi experiments
Strengths:
-carried out under controlled conditions & shares some strengths as lab.
Limitations:
-cannot randomly allocated ppts to conditions. (Confounding variables).
-IV isn’t deliberately changed so you can’t claim that IV caused observed change.
Population
-Refers to large group of individuals that a particular researcher is interested in studying.
-This is often called the target population
-It is impossible to include all members of TP, so researcher uses a sample.
-Ideally, sample is representative of TP & results can be generalised to TP.
-Most samples contain degree of bias.
Random sampling
All members of TP have an equal change of being selected.
Obtain full list and use random selected or put names in a hat.
Evaluation of Random sampling
:) unbiased so confounding/extraneous variables are equally distributed. Increases internal validity.
:) easy.
:( difficult & time consuming.
:( unrepresentative.
:( selected ppts may refuse to participate.
Systematic sampling
When every nth member of TP is selected.
Produces a sampling frame (list of TP).
Evaluation of Systematic sampling
:) objective.
:( time consuming.
:( may refuse to take part.
Stratified sampling
Reflects the proportion of people in subgroups in the TP.
Researcher identifies diff strata in population & works out proportions.
E.g. 10% whites in TP = 10% whites in sample.
Evaluation of Stratified sampling
:) representative.
:) generalisable.
:( cannot reflect every way in which people are different.
:( time consuming.
Opportunity sampling
Researchers simply select anyone who’s available.
Ask whoever is around.
Evaluation of Opportunity sampling
:) convenience sampling.
:) less costly.
:( unrepresentative.
:( not generalisable.
:( researcher bias.
Volunteer sampling
Ppts select themselves to be part of research (self selection).
Possibly through advert/poster.
Evaluation of Volunteer sampling
:) easy & minimal effort.
:( volunteer bias (could attract certain profile of person).
:( may want to impress researcher.
:( time consuming.
Ethical issues
Ethical issues arise when a conflict or dilemma arises between ppts rigjt & researchers needs to gain valuable & meaningful findings.