Cohen’s d
A measure of effect size that reflects the magnitude of the difference between the means of conditions
confidence interval for uD
A range of values of uD, one of which is likely to be represented by the sample mean in a related samples t-test
confidence interval for the difference between two u s
A range of differences between two population us, one of which is likely to be represented by the difference between two sample means
effect size
A measure of the amount of influence that changing the conditions of the independent variable had on dependent scores; may be computed as the proportion of variance accounted for
homogeneity of variance
A characteristic of data describing populations represented by samples in a study that have the same variance.
independent samples
Samples created by selecting each participant for one sample, without regard to the participants selected for any other sample.
independent-samples t-test
The t-test used with data from two independent samples
matched-samples design
An experiment in which each participant in one sample is matched on an extraneous variable with a participant in the other sample
pooled variance
The weighted average of the sample variances in a two-sample experiment
related samples
Samples created by matching each participant in one sample with a participant in the other sample of by repeatedly measuring the same participant under all conditions
related-samples t-test
The t-test used with data from two related (dependent) samples
repeated-measures design
A related-samples design in which the same participants are measured repeatedly under all conditions of an independent variable
sampling distribution of differences between means
A frequency distribution showing all possible differences between two means that occur when two independent samples of a particular size are drawn from the population of scores described by the null hypothesis
sampling distribution of mean differences
A frequency distribution showing all possible mean differences that occur when the difference scores from two related samples of a particular size are drawn from the population of difference scores described by the null hypothesis
standard error of the difference
The estimated standard deviation of the sampling distribution of differences between the means of independent samples in a two-sample experiment
standard error of the mean difference
The standard deviation of the sampling distribution of mean differences between related samples in a two-sample experiment
squared point-biserial correlation coefficient
The correlation coefficient that describes the linear relationship between scores from one continuous interval or ratio variable and one dichotomous
