Experiments Flashcards
Evaluate lab
S- reliability, can standards use procedure. More controls, less EVs, high internal validity
W- low external (ecological) validity. Artificial setting, artificial task leads to less natural behaviour. More effort and time into setting up
Evaluate field
S- natural setting provoked natural behaviour. High internal and external validity (ecological)
W- less control, more EVs. Lower internal reliability
Evaluate quasi
S- IV naturally occurring means high ecological validity. Hard to guess aims. Less researcher bias
W- less controls, more EVs. Lower reliability, time consuming/less useful have to wait for IV to naturally occur
Evaluate repeated measures
S- no participant variables. Use less participants, easier to obtain sample
W- order effects, demand characteristics
Evaluate independent measures
S- no order effects, less demand characteristics
W- participant variables, need more participants, harder to obtain sample
Evaluate matched participants design
S- no order effects, eliminates important participant variables, less demand characteristics
W- may have some participant variables. Process of matching is very time consuming
Participant variables and how to fix
Differences in participants, eg. Age, intelligence, motivation, expertise/experience, gender
Fix by using repeated measures or matched pairs. Use random allocation
Situational variables and how to fix
How the situation may affect the results, eg. Order effects, if they experience both conditions may be better or worse second time due to building skill or boredom
Fix by using counterbalancing ,ABBA method. Use independent measures or matched pairs
Environmental factors and how to fix
How the environment may affect results, eg. Time of day, temperature and noise.
Fix by imposing controls on the experiment.
Demand characteristics and how to fix
Cues in the experiment that communicates what is expected of participants which may affect results.
Fix by don’t tell participants aim of the study. Use single blind or double blind procedure
Single v double blind
Single: participant doesn’t know aims
Double: participants and researcher doesn’t know aims of the study
Alternative hypothesis
One tailed(directional), two tailed(non-directional) There will be a significant difference between (one condition) as opposed to (second condition)
Null hypothesis
Statement of no relation between IV and DV. There will be no significant difference between … any difference will be due to chance factors
Operationalisation
Process of making variables physically measurable or testable
Eg. Healthy defined as lower than 30 BMI unhealthy defined as higher than 30 BMI
Evaluate self selecting
S- quick and easy. Good for ethical issues- consent. Can request certain characteristics
W- not representative, demand characteristics, may get smaller sample, can be more expensive
Evaluate opportunity
S- quick and easy
W- not representative, small sample, researcher bias
Evaluate random
S- avoids bias, includes chance, representative
W- may not be willing to take part, equal chance to chose an outlier
Evaluate snowball
S- quick and easy, likely to get large sample size
W- not representative, people who they suggest are likely similar
Evaluate quantitative data
S- objective, reliable, easy to analyse and distinguish cause and effect, finding averages and making comparisons
W- low validity, lack of details- don’t know why
Evaluate qualitative data
S- high validity, in depth, detailed, quality, know why
W- subjective, low reliability, hard to analyse or distinguish cause and effect
Evaluate mean
S- most accurate, representative of all the data
W- time consuming, have to involve any anomalies, decimal results
Evaluate median
S- discounts anomalies
W- doesn’t take all data into account, can be unrepresentative, decimal results
Evaluate mode
S- easy to calculate, whole value, can do with qualitative data
W- doesn’t take into account all data, unrepresentative, might be no mode or multiple modes
Measures of dispersion
Range, variance, standard deviation
