Exam 9: Testing the Difference Between Two Means

A ______ is a research design in which each participant appears in all levels or categories of the independent variable.

The ______ of the sampling distribution of the difference is equal to ______.

In reporting a statistical analysis, a researcher writes "p > .05". By definition this implies that ______.

In reporting a statistical analysis, a researcher writes "p < .01". By definition this implies that ______.

A researcher hypothesizes that Drug A is more effective than Drug B. In conducting an analysis to test this hypothesis, how should the null hypothesis be stated?

A study compares 6 full-time students and 6 part-time students and obtains a value of 2.31 for the t-statistic. For α = .05 (two-tailed), which of the following is the correct way to present this analysis?

A value of -2.01 for the t-statistic necessarily implies that ______.

Imagine the value of a t-test is greater than the α = .05 critical value but less than the α = .01 critical value. Which of the following statements is true?

A researcher collects data from a group of 25 people at Time 1 and Time 2. Assuming α = .05 (two-tailed), the critical value is ______.

A researcher calculates the t-test for independent means and reports the following result: t(24) = 2.16, p < .05. This research study consisted of a TOTAL of ______ participants.

A researcher states the following hypotheses: H₀: μCity1 = μCity2 and H₁: μCity1 > μCity2. Assuming she collects data from 30 people who live in city 1 and 30 people who live in city 2, what is the appropriate critical value?

For a study analyzing the difference between test scores before and after a treatment was applied, which statistic would be most appropriate for this study?

What did the researcher do to cause the change in the shaded regions in the two distributions? "Before" "After"

______ represent(s) the variability of differences between two sample means.

One assumption related to the t-test for independent means is that of normality.

A ______ symbol is part of the ______ hypothesis, and implies this hypothesis is ______.

In writing the results of the t-test in standard APA format, the letters "n.s." imply ______.

The sampling distribution of the difference helps us determine ______.

You ______ the null hypothesis when your statistic falls in the region of ______ because this means ______.

Holding all else constant, the larger the sample size, the ______ the standard error of the difference and the ______ the value of the t-statistic (t).