Psy 173; Stats And Research Methods

Front 1

What Research Design is: A researcher randomly allocates 24depressed people to two groups. One group is exposed to 30 minutes of sunshineeach day for a week and the other group is exposed to 30 minutes of fluorescentlight each day for a week. Depression scores are compared at pre- andpost-test.

Back 1

Experiment

Front 2

What Research Design is: A researcher administers a questionnaireon attitudes to bullying to 30 6-year-olds and 30 12-year-olds from the sameprimary school. She then compares the attitude scores of the two groups.

Back 2

QuasiExperiment

Front 3

What Research Design is: The police want to know if for peoplecaught speeding there is a relationship between age and the amount by whichthey are over the speed limit.

Back 3

Correlational

Front 4

Astudy is designed to investigate whether learning a martial art increasespeople’s self-esteem which ones IV & DV?

Back 4

IV: Learning a martial art

DV: People’s self-esteem

Front 5

Aresearcher is interested in the effects of stress on decision-making. Participants are given a computer-baseddecision-making task in which their reaction time and error rate are measuredunder two conditions (low stress and high stress) which ones IV & DV?

Back 5

IV: Low stress and high stress

DV: Computer-based decision-making task

Front 6

Threats to Internal Validity (and How toAvoid them)?

Back 6

–Maturation

–Testingeffects (eg dobetter 2nd time because less anxious)

–Practiceeffects –fatigueeffects–historyeffects (events occurring between pre and post)

–Mortality/attritioneffects

–Regressionto the mean (from extreme to less extreme)

–Reactivity(egreacting to being observed)

–Biasedobservation

–Demandcharacteristics

–Hypothesisguessing

–Instrumentationeffects

Front 7

External validity?

Back 7

–Setting

–Participants

–Procedures

Front 8

Modalities of measurement (and when isappropriate to use them):

Back 8

–Behavioralmeasurement(eginterval, event recording)

–Psychophysicalmeasurement (eg justnoticeable differences)

–Physiologicalmeasurement (egheart rate, EEG)

–Objectivetests self-reportscales

Front 9

Levels of measurement:

Back 9

–Nominal(categories –eg malevsfemale)

–ordinal(rank order – eg mostpopular to least)

–Interval(rank order + distance egattitude scores)

–ratioscales (rank order + distance + absolute zero eg time)

Front 10

Types of scores for measurement:

Back 10

Raw, normative, ipsative,criterion-referenced

Front 11

Analysing and interpreting Zscore:

Back 11

Compareindividual to population with known mean and SD

Front 12

Analysing and interpreting Z statisic:

Back 12

Comparesingle sample to population and

Populationmean and SD are known.

Front 13

Analysing and interpreting Single-samplet:

Back 13

–Comparesample to population

–PopulationSD unknown – have to estimate.

Front 14

Analysing and interpreting Relatedsamples t:

Back 14

–Comparesample to itself on 2 occasions

–Comparesample to paired/matched sample

Front 15

Analysing and interpreting Independentsamples t:

Back 15

–Comparetwo unrelated samples to each other.

Front 16

Analysing and interpreting Pearson’sr:

Back 16

–Lookfor linear association between two variables.

Front 17

Nullhypothesis:

Back 17

–Nodifference between groups

–Noeffect of IV

–Noassociation between variables etc.

Front 18

pis the?

Back 18

Probability of producing results asextreme as we have through random sampling alone if the null hypothesis REALLYIS TRUE in the population.

Front 19

If p is very small (< .05)

Back 19

We infer that the null hypothesis isFALSE and that there is a REAL difference between groups/effect ofIV/association between variables.

Front 20

If p is not very small (> .05)

Back 20

We conservatively retain the nullhypothesis