t statistic (p. 218) single-sample t test (p. 219) degrees of freedom (p. 219) paired-samples t test (p. 227) | The paired-samples t test is used to compare two means for a within-groups design, a situation in which every participant is in both samples; also called a dependent-samples t test. A single-sample t test is a hypothesis test in which we compare a sample from which we collect data to a population for which we know the mean but not the standard deviation. The t statistic indicates the distance of a sample mean from a population mean in terms of the estimated standard error. Degrees of freedom is the number of scores that are free to vary when we estimate a population parameter from a sample. |