¥t-Test  [starting easy]
HProgram 3dttest
åUsed to test if the mean of a set of values is significantly different from a  constant (usually 0) or the mean of another set of values.
HAssumptions
åValues in each set are normally distributed
åEqual variance in both sets
åValues in each set are independent ˆ unpaired t-test
åValues in each set are dependent ˆ paired t-test
HExample: 20 subjects are tested for the effects of 2 drugs A and B
åCase 1: 10 subjects were given drug A and the other 10 drug B. 
íUnpaired t-test is used to test if mA = mB
íEquivalent to one-way ANOVA with between-subjects design of equal sample size ˆ can also run 3dANOVA
åCase 2: 20 subjects were given both drugs at different times.
íPaired t-test is used to test if mA = mB
åCase 3: 20 subjects were given drug A.
ít-test is used to test if drug effect is significant at group level: mA = 0