### A researcher reports t(24) = 5.30 for an independent-measures experiment. How many individuals participated in the entire experiment?

26

### For an independent-measures research study, the value of Cohen's d or r2 helps to describe

how much difference there is between the two treatments

### In general, if the variance of the difference scores increases, then the value of the t statistic

will decrease (move toward 0 at the center of the distribution)

### A research report describing the results from a repeated-measures study states the data show no significant difference between the two treatments, t(10) = 1.65, p > .05. Based on this report, you can conclude that a total of ________ individuals participated in the research study.

11

### Compared to an independent-measures design, a repeated-measured study is more likely to find a significant effect because it reduces the contribution of variance due to

individual differences

### A researcher uses a repeated-measures study to compare two treatment conditions with a set of 20 scores in each treatment. What would be the value of df for the repeated-measures t statistic?

19

### If the null hypothesis is true and there is no treatment effect, what value is expected on average for the F-ratio?

1.00

### A researcher reports an F-ratio with df = 2, 36 for an independent-measures experiment. How many treatment conditions were compared in this experiment?

3

### A researcher reports an F-ratio with df = 1, 24 for an independent-measures experiment. How many individual subjects participated in the experiment?

26

### For an experiment comparing more than two treatment conditions you should use analysis of variance rather than separate t tests because

conducting several t tests would inflate the risk of a Type I error

### In general the distribution of F-ratios is

positively skewed with all values greater than or equal to zero

### A researcher obtains an F-ratio with df = 2, 12 from an ANOVA for a repeated-measures research study. How many subjects participated in the research study?

7

### The results of a repeated-measures ANOVA are reported as follows, F(3, 27) = 1.12, p > .05. How many subjects participated in the study?

10

### critical region

extreme sample values that are very unlikely to be obtained if the null hypothesis is true

### power

the probability that the hypothesis test will reject the null hypothesis when there actually is a treatment effect (that it will correctly see the effect)

### homogeneity of variance

an assumption that two populations have equal variances (for t tests with independent samples)

### η2 (eta squared)

a measure of effect size based on the percentage of variance accounted for by the sample mean differences (similar to r2 but used in ANOVA)

### between-treatments SS, df, MS

values used to measure the differences between treatments (mean differences; used in ANOVA)

### within-treatments SS, df, MS

values used to measure the differences inside treatment conditions; assumed to measure chance or error variability

### between-treatments variability

differences from one treatment to another; a measure of mean differences (repeated-measures ANOVA)

### N

total number of scores in the entire study (when all the samples are the same size, N = kn) (ANOVA)

### when estimation is used

after a hypothesis test where H0 is rejected; when you know an effect is present; to obtain basic information

### error term

denominator of the F-ratio (ANOVA); a measure of the variance due to random, unsystematic differences

### experimentwise alpha level

overall probability of a Type I over a series of separate hypothesis tests

### post hoc tests

additional hypothesis tests done after an ANOVA to determine which mean differences are significant

### residual variance (error variance)

how much variance is expected if there are no systematic treatment effects and no individual differences contributing to the variability of the scores

### main advantage of repeated-measures ANOVA

elimination of variability caused by individual differences

### sample variance is _______ correlated with the likelihood of rejecting the null hypothesis

negatively