INTERPRETING BASIC STATISTICS EXCERPT FROM THE RESEARCH ARTICLE' DESCRIBING THE DATA 6. Does the mean pretest score what two values are the mid- The authors assessed the short-term effectiveness of a Web- for the intervention group fall dle 99.7% of participants? based alcohol education program on entering freshmen. within the range of the two 9. Assuming that the distribution Study participants were incoming first-year students at a mid- scores that you gave as your of pretest scores for the con- sized, rural, elite, private university in the Northeast. . . answer to Question 5? trol group is normal, between In June of 2006, all incoming first-year students were randomly 7. Assuming that the distribution what two values are the mid- dle 99.7% of participants? assigned to either an intervention. . or control . . . group . . . In of posttest scores for the con- trol group is normal, between 10. Assuming a normal distribu- mid-July, students in the intervention and control groups received a what two values are the tion of the pretest intervention etter, mailed to their home address, detailing the expectations for middle 95% of participants group scores, what percent- completing the online program. Both groups also received printed (approximately)? age of the participants had a materials highlighting the university's alcohol policy. Students in 8. Assuming that the distribution pretest score between 56.6 the intervention group were expected to complete the precourse of posttest scores for the con- and 91.4? knowledge test. .. . the Web-based course, and the postcourse trol group is normal, between An UD JADITZITATZ examination prior to arrival on campus. The control group partici- vbbiup. of loot lutglad. s alencoz-s salt pants were expected to complete only the precourse knowledge Questions for Discussion .slamsz smi to bru mont al srope test and the precourse survey prior to coming to campus. .. The control group was . . . invited to complete the online course during 11. If your work is correct, the consider in a study of an alco- the academic year. Situdi interval you calculated for hol intervention program for Question 8 should be larger college students? Table 1ud v:916 201052 to de8a . than the interval you calcu- 13. Would you be willing to gen- Pre- and Postintervention Knowledge Test Scores / 291052 to deal . lated for Question 7. Does this eralize the results of this study make sense? Explain. at a private university to public Control group test Intervention group test Waive CT 12. In addition to increases in scores scores Ipisitz universities? Explain. knowledge, what other out- 26 202 8 sey risito Pre Post Pre Post comes might a researcher bebristz erif yd songishib ofit M SD M SD M M SD Up/65 21 91002-3 ods Ngirls. upY il All student NOTE 1,891 73.3 9.9 83.2 12.8 74.0 8.7 88.4 6.2 participants Croom, K., Lewis, D., Marchell, T., Lesser, M. L., Reyna, V. F., Kubicki-Bedford, L., Feffer, M., & Staiano Coico, L. (2008). Impact of an online alcohol education course on behavior and harm for incoming first-year college students: Short- term evaluation of a randomized trial. Journal of American College Health, STUDY QUESTIONS oil boube fortools belepilesvoi woled ybute andT 57, 445-454. Reprinted by permission of Taylor & Francis LLC. Factual Questions stoled jommuz eri on ami ns barf 1. Just by visual inspection, which fat lliw 291092 Romes &+ of E- mont sen group had slightly higher pre- 4. Just by visual inspection, which test scores, on average? group showed a greater gain 2. On the pretest, which group from pretest to posttest, on had greater variability in their average? scores ? 5. Assuming that the distribution 3. On the posttest, which group of pretest scores for the control had less variability in their group is normal, between what scores? two values are the middle 95% of participants (approximately)? 38