Chapter 7 Flashcards
(16 cards)
T Test
Hypothesis-testing procedure in which the population variance is unknown
What does a T Test compare?
T scores from a sample to a comparison distribution called a t distribution
T Test for a Single Sample
Hypothesis-testing procedure in which a sample mean is being compared to a known population mean and the population variance is unknown
Biased Estimate
Estimate of a population parameter that is likely systematically 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 has been corrected so that it is equally likely to overestimate or underestimate the true population variance
Degrees of Freedom
Number of scores free to vary when estimating a population parameter, usually part of a formula for making that estimate
Number of scores minus 1
T Distribution
Mathematically defined curve that is the comparison distribution used in a t test
T Table
Table of cutoff scores on the t distribution for various degrees of freedom, significance levels, and one and two-tailed tests
T Score
On a t distribution, number of standard deviations from the mean (like a z score, but on a t distribution)
Repeated Measures Design
Research strategy in which each person is tested more than once
T Test for Dependent Means
Hypothesis-testing procedure in which there are two scores for each person and the population variance is not known
What does a T test for dependent means determine?
The significance of a hypothesis that is being tested using difference or change scores from a single group of people
Difference Scores
Difference between a person’s score on one testing and the same person’s score on another testing
Change Score
After score minus before score
Assumption
Condition required for caring out a particular hypothesis-testing procedure
Robustness
Extent to which a particular hypothesis-testing procedure is reasonably accurate even when its assumptions are violated
