Chapter 12 questions 1. When comparing more than two treatment means, why should you use an analysis of variance instead of using several t tests? 2. What is stated by the null hypothesis (H 0) for an ANOVA? 3. What is stated by the alternative hypothesis (H 1) for an ANOVA? . 4. An analysis of variances produces df between = 3 and dfwithin = 36. If each treatment has the same number of participants, then how many participants are in each treatment? (hint: to solve these types of problems, use your df formulas and work \"backward\" using simple algebra. So if df between is K-1, and DF between here is 3, then what is K? and so on.... 5. An analysis of variances produces df total = 42 and dfwithin = 38. For this analysis, how many treatment conditions are being compared? 6. An analysis of variance produces SStotal = 100 and SSwithin = 20. For this analysis, what is SS between? 7. An analysis of variance produces SS between = 30, SSwithin = 60, and an F-ratio with df = 2, 15. For this analysis, what is the completed F-ratio? . 8. An independent-measures research study compares four treatment conditions using a sample of n = 8 in each treatment. For this study, the four samples have SS 1 = 20, SS2 = 40, and SS3 = 14, and SS4=22. What value would be obtained for MSwithin? Chapter 12 questions 9. A researcher reports an F-ratio with df = 1, 24 for an independent-measures experiment. If all the treatments had the same number of participants, then how many individuals were in each treatment? 10. A researcher hypothesizes a difference in four autism treatments. She used ANOVA to compare 4 treatment conditions with separate samples of n=5 participants in each treatment. Some results are below. Complete the table. There are 10 total points in this problem. Fill in the table first to help answer the questions posed here. 1 point a. how many participants total? 1 point a. Was at least one treatment different from the others at an alpha of .01? Give the critical F at .01. 1 point b. Was one treatment significantly different from the others at an alpha of .05? Give the critical F at .05. 1 point c. If there was a significant finding, what step would the researcher take to see which group or groups were specifically different from the others? 1 point for each number that has a question mark next to it, 7 points in the table. Source SS Between Treatments Within Treatments Total Df MS 10 48 F=3.33