final exam due in 20 hours
combs
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KPED 4320
Independent variable Catagorical (nominal or ordinal) Numerical (interval or ratio)
Dependent variable Catagorical (nominal or ordinal) Numerical (interval or ratio)
One group (one sample) t-test: Compares sample mean to a hypothesized population mean
Dependent (paired samples) t-test: Compares two sample means from the same group of subjects e.g., test & retest or before and after
Independent (Unpaired) samples t-test: Compares sample means of the same variable from different groups e.g., experimental vs. control or group 1 vs. 2
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Examples: Independent t-test Flexibility differences between girls and
boys
Dependent t-test Pre and Post strength measurements after
6 weeks of training on the Total Gym
A t-test is performed to compare the actual difference between the means of two samples with the difference expected if only chance were operating.
Test performed on 2 independent samples experimental group treatment group
If the t-ratio exceeds the critical ratio, the null hypothesis is rejected. Chance is rejected and probable cause is assumed.
If the t-ratio does not exceed the critical ratio, the null hypotheses is accepted. The mean difference is insignificant.
t value = Difference between group means
Variability of groups
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DV: Interval or ratio
DV: Normal distribution
IV: Nominal (can only compare two means)
Mutually exclusive groups
Random selection or assignment