Some Basic Null Hypothesis Tests

What is the primary purpose of the t-test in psychological studies, as described in the chapter?

Which type of t-test is used to compare a sample mean (M) with a hypothetical population mean (μ0)?

What are the degrees of freedom for a one-sample t-test with a sample size (N) of 25?

In a one-tailed test, when is the null hypothesis rejected?

In the example study on calorie estimates of a cookie, the actual calorie count was 250. What was the mean estimate for the sample (M) of 10 students?

A dependent-samples t-test is most appropriate for which of the following research designs?

In a dependent-samples t-test, what is the first step in the calculation process?

What is the hypothetical population mean (μ0) of interest for the difference scores in a dependent-samples t-test?

In the dependent-samples t-test example, a training program was tested for its effectiveness in improving calorie estimates. The one-tailed p-value was .148. What was the correct conclusion for the researcher?

The independent-samples t-test is used to compare what?

What is the formula for the degrees of freedom for an independent-samples t-test, where N is the total sample size?

In the independent-samples t-test example comparing calorie estimates of junk food eaters and non-junk food eaters, how many total participants were in the study?

The analysis of variance (ANOVA) is the most common null hypothesis test under what condition?

The test statistic for an ANOVA is called F. What is the F statistic a ratio of?

In a one-way ANOVA, if a study has 3 groups and a total sample size of 24, what are the between-groups degrees of freedom (dfB) and within-groups degrees of freedom (dfW)?

What is the purpose of conducting post hoc comparisons after a statistically significant one-way ANOVA result?

Why do researchers typically not use a series of standard independent-samples t-tests for post hoc comparisons?

How does a repeated-measures ANOVA differ from a one-way ANOVA?

A factorial ANOVA is the appropriate analysis for which type of research design?

What does a factorial ANOVA produce for each main effect and interaction in a study?

What is the null hypothesis when testing a Pearson's r correlation coefficient?

When testing a correlation coefficient, how many degrees of freedom are there for a sample of size N?

In the example of testing a correlation coefficient between calorie estimates and weight, a sample of 22 students was used. The Pearson's r was -0.21 and the p-value was .348. What was the correct conclusion?

According to Table 13.5, what is the two-tailed critical value of Pearson's r for a sample size of 20 when α is .05?

If a researcher computes a correlation coefficient by hand and finds that the sample value is less extreme than the critical value from a table, what should they conclude?

What is the alternative hypothesis (H1) for a one-sample t-test?

In the APA style reporting of the one-sample t-test example, t(9) = -3.07, p = .01, what does the number 9 in parentheses represent?

What is the null hypothesis for an independent-samples t-test comparing two populations?

In the example comparing junk food eaters to non-junk food eaters, what was the mean calorie estimate for the non-junk food eaters?

According to the Table of Critical Values of t (Table 13.2), what is the two-tailed critical value for a t-test with 13 degrees of freedom when α is .05?

What is the null hypothesis for a one-way ANOVA with three groups?

In the one-way ANOVA example comparing calorie estimates among psych, nutrition, and dietician majors, the calculated p-value was .0009. What is the correct conclusion?

Which value from the ANOVA output table in the text (Table 13.4) represents the mean squares within groups (MSW)?

What is the primary advantage of using a repeated-measures ANOVA for a within-subjects design compared to a one-way ANOVA for a between-subjects design?

If a researcher is studying the effects of participant major (psychology vs. nutrition) and food type (cookie vs. hamburger) on calorie estimates, what type of analysis should be used?

The test for a correlation coefficient can be one-tailed if the researcher does what?

If a researcher found a Pearson's r of .550 with a sample of 10 for a two-tailed test (alpha = .05), what should they conclude based on Table 13.5?

What is the key disadvantage of a one-tailed test?

In the dependent-samples example, the mean of the difference scores was 8.50 with a standard deviation of 27.27 for 10 participants. What was the calculated t-score based on the formula image provided?

If you reject the null hypothesis in a one-way ANOVA, what can you conclude?

According to the description of the F distribution for ANOVA, what are its typical characteristics when the null hypothesis is true?

In the one-way ANOVA example, the critical value of F (Fcrit) with 2 and 21 degrees of freedom was 3.467. The calculated F score was 9.92. What does this comparison indicate?

Which of the following is listed as a modified t-test procedure used for post hoc comparisons to control for Type I error?

If a sample has a Pearson's r of .200 and a sample size of 90, what is the conclusion for a two-tailed test with alpha at .05, according to Table 13.5?

Which null hypothesis test is used for between-subjects designs with a single independent variable and more than two groups?

What does a dependent-samples t-test become after the first step of creating difference scores is completed?

If a researcher conducts a one-tailed test expecting an increase in scores but finds a large decrease, what will be the outcome of the null hypothesis test?

In the context of ANOVA, the test statistic F is a ratio of two estimates of what?

According to Table 13.2, for a two-tailed test with alpha at .05, as the degrees of freedom increase from 3 to 100, what happens to the critical value of t?

What is the alternative hypothesis for a test of a correlation coefficient?