Monthly Schedule

(STAtistics, Period D)

W 10/1/08	Test #2. This test is cumulative over chapters 1-3. Among other things, you are expected to know all of the LSRL Top Ten items, many of which were discussed in class yesterday.
Th 10/2/08	HW due: Read pp. 176-177, 179-188. There is no written work (other than your reading notes, of course), but you should work through Example 4.1 in detail. Your calculator may be spot-checked for evidence that you worked through the example on your own. Your lists L1, L2, and LOGY should be in place and populated with the values that the example instructs you to produce.
F 10/3/08	HW due: Read pp. 190-195 and the summary on p. 197; write #4.10 (including writing the scatterplot and residual plot in part (a)) and #4.70 below. 4.70 Recall Farmer Bob’s (year, wheat) dataset from yesterday’s class. It is reproduced below in case you have lost it. {(86, 350), (87, 380), (88, 410), (89, 445), (90, 485), (91, 530), (92, 580), (93, 645)} (a) Make a scatterplot. Label your axes. The explanatory variable should be year, and the response variable should be wheat (in bushels). (b) Write the LSRL equation and use it to predict Farmer Bob’s wheat production in 1994. Keystrokes: STAT CALC 8 L1,L2,Y1 ENTER to get LSRL, Y1(94) ENTER to get predicted value. However, you must show your work on the second part using the AP standard approach: formula, plug-ins, boxed answer with units. For example, if the LSRL is , you would show your work as follows: (c) Overlay your LSRL on your scatterplot from part (a) as a light dashed line. (d) Make a residual plot for the LSRL model. Label the values on your x and y axes. (e) Write the ExpReg equation and use it to predict Farmer Bob’s wheat production in 1994. Keystrokes: STAT CALC 0 L1,L2,Y2 ENTER to get exponential equation, Y2(94) to get predicted value. As in part (b), you must show your work for the predicted value using the AP standard approach. Box your answer with units. (f) Overlay your exponential curve model on your scatterplot from part (a) as a solid line. (g) Which model appears to fit the data better? (h) Make a residual plot for the exponential regression model. Label the values on your x and y axes. Although the residual plot is still “bowl-shaped,” how can you tell that this is an improvement over part (d)? (i) Explain briefly why the predictions in both (b) and (e) are unreliable. (j) Of the predictions in (b) and (e), which is probably better? Why?
M 10/6/08	HW due: Take a second stab at the HW that was due on Friday. Everybody needs to do this. Also please read Mr. Hansen’s three rules and Mr. Hansen’s policies concerning absences, both of which are available as links on the main modd.net page.
T 10/7/08	HW due: Read the Wikipedia article about Anscombe’s Quartet (four data sets that can be summarized by a single slogan: Look at your data!) and this article about the shortcomings of PowerPoint; write #4.6abcde.
W 10/8/08	HW due: Read pp. 206-214; write #4.12, 4.22, 4.23, 4.24. Note: There will be no “Quick Study” quiz this week.
Th 10/9/08	HW due: Read pp. 215-231, omitting exercises; write the protocol exercise below. Do read all the examples, such as Example 4.11 on p. 220. The total amount of reading is therefore about 9.5 pages. Protocol Exercise: Write out the steps for a randomization protocol that will enable our class to be divided randomly into 4 groups of 3 people for the next group project, which will be a taste test. Note: This is not the taste test protocol, only the randomization protocol for the selection of groups and group leaders. The requirements are that everyone should have new group members, Kate should be included in one of the groups, and the 4 group leaders should be people who did not have a chance last time.
F 10/10/08	No school (faculty professional day).
M 10/13/08	No school (holiday).
T 10/14/08	HW due: Each group should submit a draft methodology statement and timeline, preferably typed and double-spaced. The group leader is responsible for this submission, and if absent for any reason, is expected to deputize another group member to deliver this document on time. Underlining denotes group leader. Group 1: Stefan, Eddie, Ted. Working concept: 3 colas. Group 2: Kate, Grenville, Patrick. Working concept: 2 coffees. Group 3: Ben, Charlie, Sam. Working concept: 2 pizzas. Group 4: Cameron, Doug, Jimmy. Working concept: 3 waters (2 bottled, 1 tap). You may change your working concept if you wish. Be sure to describe all of the following in detail: · Your procedure for selecting subjects. A convenience sample is acceptable, as long as no STAtistics class members are used as subjects. · Your procedure for randomizing subgroup assignment and/or the order in which the taste data are gathered. · Any other features of your methodology that will need to be systematically implemented, such as temperature control or palate cleansing. You will not begin gathering any data until your methodology has been discussed and approved. There are a minimum of 50 data points required, but if you are gathering random-order data of more than one substance per subject, you may use fewer subjects. For example, group 4 will need only 17 subjects, since they will be gathering at least 3 data readings from each subject. Group 2 may use fewer data points because of the logistic difficulty and cost associated with procuring an adequate volume of temperature-controlled pizza. If you have any questions, please e-mail me with __ (two underscores) at the beginning of your subject line so that the message is not treated as spam. Final due date for the project is October 27 or 28.
W 10/15/08	HW due: Revised methodology and timeline, please. Use the feedback that was furnished in class (or in the case of the pizza group, by e-mail) to help guide your revisions. For your timeline, be sure to break the project into tasks: initial data collection complete by ___ , follow-up data collection for subjects missed on first pass complete by ___ , meeting to enter and begin analyzing data on ___ , etc. The plan is a skeleton that guides your project. We know that some dates may shift (and we can even build in some cushions here and there), but without some sort of plan, we have no confidence that we will achieve our goal. A Washington Post quiz is also likely this week.
Th 10/16/08	HW due: A second revision (third version) of your methodology and milestones, please. Make sure to have some real details in your milestone plan. Also read this article on an interesting statistical controversy. There may be a quiz on the reading, since the “Quick Study” has apparently been dropped by the Post.
F 10/17/08	HW due: Read pp. 245-255; write #4.64. Also, get started on your group projects. For planning purposes, please be aware that Monday’s class period will be a full period for group meetings and/or data gathering.
M 10/20/08	HW due: Study for Tuesday’s test and work on your group project. In class: Report to class for roll call. Dr. Bennett will monitor your work. The time is yours to use in any useful, productive fashion. Group project meetings and/or studying for tomorrow’s test are strongly recommended. I can be reached in the evening by e-mail.
T 10/21/08	Test #3 (cumulative through p. 255 of textbook). Among other recent skills, you are expected to be able to perform linear, power, and exponential regression in the manner of the “Farmer Bob” problem, including residual plot construction and analysis. The Farmer Bob problem was covered in class in excruciating detail. If you missed it, get somebody’s notes. If your friends all took lousy notes, then acquire some additional friends. All of your terminology and notation (sample mean, sample variance, population mean, population variance, etc.) are still fair game, as are the LSRL Top Ten features. Simpson’s Paradox is also included, as well as the following terms (this list is not comprehensive): common response confounding lurking variable response bias voluntary response bias undercoverage house effect anecdotal data blinding, double blinding outlier (univariate) outlier (regression) influential observation residual two-way table marginal, conditional, and joint probabilities (see below) scales: nominal, ordinal, interval (a.k.a. arithmetic), and ratio (a.k.a. absolute) Examples of conditional and marginal probabilities in a two-way table Suppose that we have gathered the following statistics from a census of 117 students: We have the following marginal probabilities: P(sleepy) = 40/117 P(grumpy) = 32/117 P(friendly) = 37/117 P(male) = 78/117 P(female) = 39/117 We have the following conditional probabilities, where the “|” symbol is read as “given”: P(sleepy | male) = 32/78 P(sleepy | female) = 8/39 P(grumpy | male) = 20/78 P(sleepy grumpy | male) = 52/78 P(male | grumpy) = 20/32 P(female | sleepy) = 8/40 We have the following joint probabilities, where the “” symbol is read as “and”: P(sleepy male) = 32/117 P(grumpy male) = 20/117 P(sleepy grumpy) = 0 P(spastic male) = 6/117
W 10/22/08	HW due: Read this week’s Quick Study (click here or see your e-mail) in preparation for an open-notes quiz. Or, if you prefer, you can bring a newspaper or magazine article from an actual newspaper or magazine (not a printout from an online source) that shows a methodological discussion. If you choose the article option, you would be expected to make a brief “show and tell” presentation to demonstrate that you read the article and learned something of value from it.
Th 10/23/08	HW due: #5.2, 5.4. You are exempt from this assignment if you check in with me at the Choral Festival at the Cathedral on Wednesday night. I will be sitting near the front of the sanctuary. Find me either before or after the performance. If you are in the chorale, I may or may not be able to spot you, so be sure to see me in person.
F 10/24/08	HW due: Read pp. 256-261; write #5.16.
M 10/27/08	Optional due date for group project. Groups that submit their final writeup before 4:00 p.m. today will receive a bonus of 5 points per group member.
T 10/28/08	Second group project (100 points) due at 4:00 p.m. Groups that turned this in yesterday have a night with no work.
W 10/29/08	HW due: Read pp. 265-276; write #5.30a, 5.37. For #5.37, use your own words, not the words in the back of the book. Remember, since this is Wednesday, there is also a reading quiz on the Quick Study (or you can bring an article for show and tell).
Th 10/30/08	HW due: Read pp. 277-284; write #5.38, 5.46.
F 10/31/08	End of first quarter. There is no additional HW due today, but make sure that you are up to date on all recent assignments, because some may be scanned a second time.

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Last updated: 06 Nov 2008