testing procedure where the population variance is unknown.
testing procedure where a sample mean is being compared to a known population mean and population variance is unknown
estimate of population parameter that is likely to overestimate or underestimate the true value of the population parameter.
unbiased estimate of the population variance
estimate of the population variance, based on sample scores, which have been corrected so that it is equally likely to over or under estimate the true population variance.
degrees of freedom
number of scores free to vary when estimating a population parameter
table of cutoff scores on the t distribution for various degrees of freedom, significance levels, and one and two-tailed tests.
curve that is the comparison distribution used in a t test
on a t distribution, number of standard deviations from the mean
repeated - measures design
each person is tested more than once
testing procedure which their is two scores for each person and the population variance is not known
difference between a person's score on one testing and the same person's score on another testing
extent to which a particular hypothesis - testing procedure is reasonably accurate
testing procedure where there are two separate groups of people tested and in which the population variance is not known.
distribution of differences between means
distribution of differences between means of pairs of means.
pooled estimate of the population variance
in a t test for independent means, weighted average of the estimates of the population variance from two samples.
average in which the scores being averaged do not have equal influence on the total.
variance of the distribution
one of the numbers figured as part of a t test for independent means
standard deviation of the distribution
in a t test for independent means, square root of the variance of the distribution of differences between means.
special average influenced disproportionately by smaller numbers.