New Seats Block 1

New Seats Block 2

Warm-up Day before Ch. 4 Test Suppose you want to study the effect of calculator use (yes or no) on the mathematics course grade for 6 th grade students at a local middle school. In the upcoming school year, the middle school will have a total of th grade students. a.You are given permission to randomly assign students to their math classes. At this middle school there are 25 students/classroom. Describe an experiment for such a study using the classroom as the experimental unit. Be sure to describe all needed randomization and identify the treatment(s) and the response variable. b. Name the primary source of within treatment variation for your design.

Student of the day! Block 1

Student of the day! Block 2

4.3 #26 E#26. a. The factors are types of powder and oven temperature. The levels are the two types of powder and the three different oven temperatures b. The powder should be randomized into which batches will be put into the different 3 temperatures. Also since there is only one oven the powder should be randomly placed in different areas of the oven. c. The metallurgist could have an assistant carry out the experiment. The metallurgist can then evaluate each of the results without knowing which powder was used and temperature. The assistant could then have a system where the evaluations could be linked to the different treatments.

4.3 E #27 and 4.4 E #34 a. The experimental units are the dormitories. b. There are 20. c. This is an experiment because half the dormitories will get the special soap (treatment), the other half will get regular soap. 4.4 E #34 a. This is a completely randomized design where schools are randomly assigned to two groups, one group for each treatment. Treatments: extensive calculator use or limited calculator use Experimental unit: each school Blocks: none b. This is a randomized block (paired comparison) design. Treatments: extensive calculator use or limited calculator use Experimental unit: each school Blocks: the pairs of schools with similar gain scores from the previous year

4.4 E# The 23 experimental units are assigned randomly to the four groups. The treatment for one group is a special exercise program. The treatment for another group is a standard exercise program. The other two groups were not given any special exercise or instructions but one group had to check in every week. The other group had to check in only at the end of the experiment. The response being measured was when the infants were able to walk on their own.

Directions for Chapter Review out of the textbook Complete Textbook review pg 279 E #41 – 46, 55, pg 284 AP#1-5 in silence for 30 minutes. When the 30 minutes are up you are allowed to discuss your answers. During this time I will finish the notebook check. 1) 4.1 2) 4.2 and 4.3 3) pts each x 3 = 75 pts 15 pts for notes 10 pts for warm-up 25 definitions, 1 pt each for 25 pts If you finish early complete the Review. The test is not in the same format as the Review. The test will ask about definitions with a word bank, short answer, and two free response. There may be two multiple choice questions.

Answer to textbook Review E #

Textbook Review E44. a. Take home pay is less than gross pay because gross pay is taxed and is susceptible to deductions. b. Worker might report an income that is too high. They might give the wrong job title. They might include bonuses in income. E45. This is a judgment sample. If an actor’s pay is in the book, they are probably famous. Not all actors are famous. Therefore, the average reported will be too high.

E#46 and AP # E#46. Method 1 is sized biased. Larger states have more senators so randomly selecting a senator give bias to larger states. Method 2 is not sized biased. E#55 a. This is an observational study, because the subjects were asked which diet they followed. None of the subjects were assigned a special diet. b. People could have lied or been inaccurate about what they ate. Also those following the Mediterranean diet are most likely Greek and will have a different lifestyle than the Americans. c. Confounding variable is lifestyle. One lifestyle may be less stressful and lend itself to more physical activity which reduce the likelihood of heart attacks. AP 1. C 2. E 3. B. 4. A 5. A

Review Answers 1. A random selection in a sample survey reduces bias in such a way that the results represent the population. 2. In an experimental study, treatments are assigned to the subjects under study, whereas in an observational study, the conditions of interest are already built in. 3. C8. D 4. B9. C 5. D, because this will reduce within treatment variability 6. C10. B 7. A

Review Answers Continued… 11. An example could be taking a random sample of college level biology class students and trying to estimate the average class size. By taking a random sample, students in the larger classes are more likely to be selected, thus creating a larger result. Another example is selecting states for surveys by dropping grains of rice on a map. Larger states are more likely to be selected due their larger representation on the map. 12. Temperature and time of year are lurking variables in the strongly associated variables.

Vocabulary Demystified Sampling Response BiasExperimental Study Biased nonresponseblind study Non -or unrepresentative incorrectdouble-blind study Voluntary questionnairematched pair Judgment block design Convenience Random types of Sampling Observational Study Simple random sample Study where there is no treatment units are Stratifiednot manipulated … ( There is a matched pair…) Systematic Cluster Two-stage cluster

Common quiz Mistakes Voluntary sampling is a biased sampling method, because the units self-select themselves for the sample. Block design does not have to be male and female for blocks. Just had to describe how the participants would be divided into groups to try the 3 cookies in different orders OR just try one cookie. #8 FORM A # 8 FORM B

Practice Test Answers From an old Practice Test 14. The experiment can be improved by changing the order in which the participants try the three chips. Also the researchers should randomly select participants for the study. Researchers should also try more than one location to select participants. 15 a. 15 b. Explain how you would assign each male and female a # to randomly assign 5 to Treatment A, the 5 males or females remaining are placed in Treatment B.