280 likes | 539 Views
Hypothesis testing. z-score testCompare sample to a known populationPopulation variance is knownOne-sample t testCompare sample to a known population Population variance is unknownIndependent samples t testCompare two samples from unknown populationsBoth population variances are unknownBe
E N D
1. Independent samples t test
2. Hypothesis testing z-score test
Compare sample to a known population
Population variance is known
One-sample t test
Compare sample to a known population
Population variance is unknown
Independent samples t test
Compare two samples from unknown populations
Both population variances are unknown
Between-subjects design
Related samples t test (paired t test)
Compare sample difference between two conditions
Population difference and variability are unknown
Within-subjects design
3. Hypothesis testing So far, we have looked only at using one sample as the basis for drawing conclusions about one population
However, it is common in research to compare two (or more) sets of data.
E.g.:
- compare men's and women's attitudes toward abortion
- compare the effectiveness of two teaching methods
- compare patients' level of depression before and after therapy
4. Two general research strategies Independent samples
the two sets of data come from completely separate samples
e.g., men and women
an independent-measures t test is used
between-subjects design
Related samples
the two sets of data could come from the same sample
e.g., people with depression, before and after therapy
a related-samples t test is used
within-subject design
5. Independent samples t test