Chapter 9

The researcher obtained a significant F from the ANOVA. Omega squared was found to be .30. How is this result appropriately interpreted?

30% of the total variance is accounted for by the treatments

A study involves the comparison of two instructional methods on achievement in math. Two classrooms are used; one method is administered in each classroom. The researcher notices that the pretest scores show differences between the two groups. To control for the influence of the pretest scores on the posttest scores, the researcher should use:

ANCOVA

If the null hypothesis is false, one may assume the research hypothesis to be the explanation for the results if:

All other possible explanations have been controlled

A researcher sought to find out which of two exercises was more effective in building endurance. One group used exercise A, and another group used exercise B. At the end of study, how should the researcher compare the scores of the two groups?

An independent t test

To find out which of two methods for learning a motor skill is more effective, what is the correct statistical analysis?

An independent t test

When the purpose of the research is to determine the effects of one independent variable (four groups) on one dependent variable (self-concept), what is the best choice of a statistical analysis?

Analysis of Variance

A researcher wishes to determine whether a treatment group made a significant improvement from the pretest (M=25) to the posttest (M=30). What is the correct statistical test to use to compare the two means?

Dependent t test

For a study with two (or more) independent variables, such as type of instruction and sex, and one dependent variable, such as achievement, what is the most appropriate analysis technique?

Factorial ANOVA

Which of the following statements does not describe an advantage of repeated measures?

Repeated measures can eliminate the influence of some unwanted variable.

Use of a one-tailed versus a two-tailed test of significance of the difference between two samples means depends on:

Whether the difference is expected to be in one direction only