The grading of the exams went smoothly, with the entire set of 110,000 exams graded by the close of business on Wednesday night. Although students from other schools seemed to think that the problems were hard, the teachers and professors who graded the tests were not complaining about a lot of low scores. I guess that's a good sign!
The chief reader (Christine Franklin, from UGA) evaluates the distribution and sets the cut points for the different final scores based on how students performed on the repeated questions from previous years. That done, the scores have to be approved by the AP psychometric gurus and processed for release to students. In other words, your scores should be available on time.
My role at the reading was a little different this year. In past years I've been assigned to a grading group of 12 people headed by two table leaders, then trained to grade two problems from the regular exam according to the rubric. For seven full days the people in each group grade those two problems. For instance, a reader may grade question #5 (the moose problem) and the table leader checks the scoring. Since there are six problems on the test and this year over 500 readers, there are a lot of people grading the same problem. Once a problem has been graded, that test booklet is bundled up and passed to a group that grades another question, and the process continues until all of the problems have been graded. If a reader has a question, she asks her grading partner, then her table leader. If the problem is not yet resolved, the question goes to the question leaders.
This time Ms. Franklin put me in a grading group with a bunch of REALLY experienced readers (famous and incredibly important people in statistics, like one of the authors of a popular textbook) who graded the make-up exam. We also graded two questions each (plus one from the regular exam), but we were the only ones to grade those problems. When we had questions, the people who wrote the rubric were right at our tables to answer and help us resolve any issues. Since none of you took the make-up exam this year, I never had to worry about accidentally grading one of my own students' tests, but every time readers commented on how great an answer was I told them that it must have been one of MY students. :) The trick with grading the make-up exam is that we can never divulge the contents of the exam to anyone, but that shouldn't be a problem because I have already forgotten it all!
You may be wondering (as I did) how I qualified for that special grading group. I think that they chose the very best former table leaders and other important people they could find, then filled in the rest with some experienced people from Georgia. Clarification: some of the important people were also from Georgia, so the line between the superstars and the poser (me) was blurred. Oh yeah, and they said that we we were selected because we were fast graders. I thought you'd enjoy that.
A few students, usually those who are stumped by a problem, write notes to the graders asking for mercy or generosity in grading. I'm sure they're joking, but they might be surprised to know how wonderful, helpful, and patient the graders really are. About half of the graders are college instructors who give up a week of their summers or coveted summer courses to validate this process for our students. The high school teachers are the ones who have attended or led workshops and conferences in statistics. Some of them haven't even ended their school years yet and have to pay their school districts back for the substitutes they needed. These people write the creative lessons published in books and shared online. They write the the textbooks and the study guides. They do it for students. They spend all day grading exams, then come back after dinner to hear a guest speaker talk about mathematical modeling or to share best practices. They are on constant lookout for ways to help their students understand statistics better.
This goes for the English Lit, French, and APUSH graders who were there at the same time, too.
I am honored and humbled to be invited to participate in this process with these amazing people.
Video time: http://www.youtube.com/watch?v=zTPhZcxnBSE&feature=related
http://www.youtube.com/watch?v=Ac3CtHYo5rY&feature=related
http://www.youtube.com/watch?v=IKkBBVxI5qU&feature=related
Friday, June 20, 2008
Monday, May 19, 2008
Final exam preparation
(1) All classes have received their take-home portion of the final exam. The problem must be worked out completely, correctly answering the questions posed , on a separate sheet of paper. For underclassmen, the graph may be drawn on the question sheet itself. This is an individual assignment. You are not to collaborate on this problem. The problem is due on the day of your final.
(2) The in-class part of your final will consist of 21 problems from the practice multiple choice tests. The content relates to second semester topics.
Show me your best work!
(2) The in-class part of your final will consist of 21 problems from the practice multiple choice tests. The content relates to second semester topics.
Show me your best work!
Sunday, May 04, 2008
The practice tests
For Tuesday: Dress in layers because the gym is CCOOOOOOOOOOOOLLLLLLDDDD!
Replace your batteries if it has been a while since they were changed. Remember to run CtlgHelp (an APP) and Diagnostics ON (use catalog to find this).
Bring your student ID, pencils, and a pen.
Come to the outside classroom a little BEFORE THE END OF third period. You need to eat before you test. I'm bringing food.
Estudiantes del AP Espanol: We will save food for you. Come out to the outdoor classroom after the other exam.
DO NOT BRING study guides, textbooks, cell phones, i-pods, etc.
Post any questions to me by 9:00 for best shot at getting an answer.
GO TROJANS.
It's about 5:40 PM and I'm finally home. Please call if you have an urgent need to meet at CiCi's. 7/ 354 . 1791 (number is broken into pieces to discourage phishers).
I WILL NOT be at CiCi's at 2:00. You folks can still go and be an amazing, productive group, though. Be smart.
I will touch base again when I re-enter the cyper-world.
There will be ONE MORE multiple choice test on Thursday. The format is the same as the previous tests. This grade will replace the lowest of the multiple choice test grades. Be prepared.
The practice tests have been graded, the grades posted, and the adjustments are complete. There are three grades representing the original test score or a measure of improvement as follows:
If the original score on test 2 > test 1, then the original test 2 score is inserted as test 1's score as well.
If the score on test 3> test 2, then test 3's score is inserted as test 2's score as well.
No, if test 3 > test 2> test 1 you DON'T get test 3 posted three times.
Congratulations to those who scored over 100% on test 3. The highest score was 33 correct with 2 wrong for a raw score of 32.5 and a posted score of 162.5. That score also replaced the student's lower test #2 score.
OK. Have you ever had something in your eye and you just couldn't bring yourself to cry to wash it out? This would do the trick:
http://youtube.com/watch?v=WIxtxwiqK-s
I warned you.
Find some time this weekend to do the practice exam in the packet handed out on Thursday, but your next assessment is MULTIPLE CHOICE. Practice with a study guide. Find the topics that you don't remember. Brush up. Take a deep breath. See you Sunday for pineapple pizza?
- - - - -
Today's multiple choice test scores are posted to I-Parent. The next test will be Thursday.
The third opportunity for the practice free response test is Wednesday afternoon.
Video alert: The movie Wargames (released 25 years ago!!) is on amc right now. The best part is toward the end of the movie, when the computer gets smart.
Replace your batteries if it has been a while since they were changed. Remember to run CtlgHelp (an APP) and Diagnostics ON (use catalog to find this).
Bring your student ID, pencils, and a pen.
Come to the outside classroom a little BEFORE THE END OF third period. You need to eat before you test. I'm bringing food.
Estudiantes del AP Espanol: We will save food for you. Come out to the outdoor classroom after the other exam.
DO NOT BRING study guides, textbooks, cell phones, i-pods, etc.
Post any questions to me by 9:00 for best shot at getting an answer.
GO TROJANS.
It's about 5:40 PM and I'm finally home. Please call if you have an urgent need to meet at CiCi's. 7/ 354 . 1791 (number is broken into pieces to discourage phishers).
I WILL NOT be at CiCi's at 2:00. You folks can still go and be an amazing, productive group, though. Be smart.
I will touch base again when I re-enter the cyper-world.
There will be ONE MORE multiple choice test on Thursday. The format is the same as the previous tests. This grade will replace the lowest of the multiple choice test grades. Be prepared.
The practice tests have been graded, the grades posted, and the adjustments are complete. There are three grades representing the original test score or a measure of improvement as follows:
If the original score on test 2 > test 1, then the original test 2 score is inserted as test 1's score as well.
If the score on test 3> test 2, then test 3's score is inserted as test 2's score as well.
No, if test 3 > test 2> test 1 you DON'T get test 3 posted three times.
Congratulations to those who scored over 100% on test 3. The highest score was 33 correct with 2 wrong for a raw score of 32.5 and a posted score of 162.5. That score also replaced the student's lower test #2 score.
OK. Have you ever had something in your eye and you just couldn't bring yourself to cry to wash it out? This would do the trick:
http://youtube.com/watch?v=WIxtxwiqK-s
I warned you.
Find some time this weekend to do the practice exam in the packet handed out on Thursday, but your next assessment is MULTIPLE CHOICE. Practice with a study guide. Find the topics that you don't remember. Brush up. Take a deep breath. See you Sunday for pineapple pizza?
- - - - -
Today's multiple choice test scores are posted to I-Parent. The next test will be Thursday.
The third opportunity for the practice free response test is Wednesday afternoon.
Video alert: The movie Wargames (released 25 years ago!!) is on amc right now. The best part is toward the end of the movie, when the computer gets smart.
Tuesday, April 15, 2008
Chapter 14 - The final frontier
Inferences for regression
HW for Monday: Entire free response test from 2004. Take 90 minutes under test conditions.
HW for Friday: Problem 6 from 2007 AP exam.
HW due Thursday: Problems 14.11 and 14.18 PLUS the chapter summary.
HW due Wednesday: Problem 2 from the 2006 exam. Language is critical. If you do not know what the question asks, look at Example 14.5 in the text. Respond IN CONTEXT. There will be no partial credit for this problem.
DO NOT FORGET that your one-page summary of the selected chapter is due Thursday.
This chapter explains how to use the slope of a LSRL calculated from a sample and the std dev of the slopes
Why are there only n-2 degrees of freedom?
Why do we make such a big deal about s sub-b1 being the std dev of the slopes?
HW for Tuesday: problems 14.1 and 14.2 from the text.
Chapter summary due Thursday.
HW for Monday: Entire free response test from 2004. Take 90 minutes under test conditions.
HW for Friday: Problem 6 from 2007 AP exam.
HW due Thursday: Problems 14.11 and 14.18 PLUS the chapter summary.
HW due Wednesday: Problem 2 from the 2006 exam. Language is critical. If you do not know what the question asks, look at Example 14.5 in the text. Respond IN CONTEXT. There will be no partial credit for this problem.
DO NOT FORGET that your one-page summary of the selected chapter is due Thursday.
This chapter explains how to use the slope of a LSRL calculated from a sample and the std dev of the slopes
- to create a confidence interval for capturing the slope of the true equation through ALL the data and
- to make decisions about a hypothesized linear relationship.
Why are there only n-2 degrees of freedom?
Why do we make such a big deal about s sub-b1 being the std dev of the slopes?
HW for Tuesday: problems 14.1 and 14.2 from the text.
Chapter summary due Thursday.
Wednesday, April 02, 2008
Chapter 13 Inferences using Chi-square
Your Chapter 12 tests are available Thursday morning for pick up in room 313. I have posted an answer key outside room 313 for comparison.
What can you do to prepare for Thursday's test? Have you taken the online quiz? Select the link to the right>>>>>>
Have you used a study guide? You have now learned almost everything from the syllabus for the exam, so get to work!
Have you read the chapter in the text? Y, M, and M explained these concepts differently. If you didn't "get it" the way I explained it, you might like their version.
Did you google lesson chi-square test or something like it? Sometimes you can find nifty applets that make the concepts clear.
See you on Thursday.
HW due Wednesday, April 2: Complete 5 problems from the chapter review (NOT 28 or 29) in preparation for Thursday's test.
HW due Tuesday, April 1: Read pages 717 through 724. Do problems 13.14 and 13.16.
HW due Monday, March 31: Problems 28 and 29 (which requires simulation). Leave yourself enough time to do problem 29 or go to CiCi's.
HW due Friday: Problems 13.9, 13.10, 13.12.
HW due Thursday: Write up your answer to the free response problem handed out in class AND work problems 13.1 and 13.3.
We will study three different types of test that use chi-square methods in this chapter:
goodness of fit: compares one sample distribution to an expected distribution to see if it matches the expected counts closely or not (for example, comparing a sample of M&Ms by color to the % the company says it produces).
test of independence: determines whether there is evidence that a relationship exists between at least two categorical characteristics within a population based on the counts of observations in one sample (for example, analyzing applications to law school to see if undergraduate major and admission rate have a relationship).
test of homogeneity: compares counts within the distributions of two or more comparable samples to see if there is a significant difference inthe mixes (for example, comparing color distribution of a sample of milk chocolate M&Ms to the distribution of a sample of peanut M&Ms to see if there is a difference).
Each of the methods uses the formula sum [(O-E)^2/E]. This is the formula that Dr. Chuck Tate had written on his "grill" in the Statz 4 Life video.
Our plan is to do lots of labs and practice writing free response answers for the next few days. Our test is Thursday of next week.
For more information, scroll down to the Chapter 13 information from 2006 and 2007 on this blog.
Our probability lab is a week from Friday. We need parent volunteers to help with the activities. Please ask your parents to email me if they want to be part of this fun experience. They'll have a blast.
What can you do to prepare for Thursday's test? Have you taken the online quiz? Select the link to the right>>>>>>
Have you used a study guide? You have now learned almost everything from the syllabus for the exam, so get to work!
Have you read the chapter in the text? Y, M, and M explained these concepts differently. If you didn't "get it" the way I explained it, you might like their version.
Did you google lesson chi-square test or something like it? Sometimes you can find nifty applets that make the concepts clear.
See you on Thursday.
HW due Wednesday, April 2: Complete 5 problems from the chapter review (NOT 28 or 29) in preparation for Thursday's test.
HW due Tuesday, April 1: Read pages 717 through 724. Do problems 13.14 and 13.16.
HW due Monday, March 31: Problems 28 and 29 (which requires simulation). Leave yourself enough time to do problem 29 or go to CiCi's.
HW due Friday: Problems 13.9, 13.10, 13.12.
HW due Thursday: Write up your answer to the free response problem handed out in class AND work problems 13.1 and 13.3.
We will study three different types of test that use chi-square methods in this chapter:
goodness of fit: compares one sample distribution to an expected distribution to see if it matches the expected counts closely or not (for example, comparing a sample of M&Ms by color to the % the company says it produces).
test of independence: determines whether there is evidence that a relationship exists between at least two categorical characteristics within a population based on the counts of observations in one sample (for example, analyzing applications to law school to see if undergraduate major and admission rate have a relationship).
test of homogeneity: compares counts within the distributions of two or more comparable samples to see if there is a significant difference inthe mixes (for example, comparing color distribution of a sample of milk chocolate M&Ms to the distribution of a sample of peanut M&Ms to see if there is a difference).
Each of the methods uses the formula sum [(O-E)^2/E]. This is the formula that Dr. Chuck Tate had written on his "grill" in the Statz 4 Life video.
Our plan is to do lots of labs and practice writing free response answers for the next few days. Our test is Thursday of next week.
For more information, scroll down to the Chapter 13 information from 2006 and 2007 on this blog.
Our probability lab is a week from Friday. We need parent volunteers to help with the activities. Please ask your parents to email me if they want to be part of this fun experience. They'll have a blast.
Saturday, March 22, 2008
Chapter 12 Inference for proportions (Yeah!)
HW for Monday: In preparation for Tuesday's test, the MINIMUM assignment is to work four problems (your choice) from the Chapter Review. This means that at least four problems have to be completed correctly. For instance, if problem 28 had been in the review section, your answer would include a complete hypothesis test or confidence interval--not just your opinion.
HW for Friday: 12.25, .26, and .28.
March Madness: post your NCAA men's basketball brackets at CBSSportsline with the Linnerstats bracket. The password for the bracket is just what you'd expect, gogators. If you are a bracket rookie, this means that you predict the winners of the 63 games in the NCAA basketball championship tournament. The software at CBSSportsline makes it really easy. You have to work fast. . . the brackets close soon.
HW for Thursday: Write up the inferences (hypothesis test and confidence interval) you generated today using the fluffy pom poms. Make your answers complete and correct. First period, please be prepared to meet me in our temporary location after our brief homeroom first thing Thursday.
HW due Wednesday: Complete write-up (PHANTOMS) of the Skittles hypothesis you generated in class. (Run a 1-proportion z-test on a large-enough sample of Skittles. The size of the sample depends on what you consider a "success.")
HW due Tuesday, March 18th: 12.13, 12.15, 12.16, 12.17. Please note: The answers in the back of the book for problem 13 used 0.33 as the value for 1/3. Obviously, this is not going to give you the "correct" answer. Please use 1/3 instead of their estimate and realize that your answers will be a little different from theirs, but yours will be correct! You can check your answers using the STAT TEST 1-PROP Z TEST on the calculator. The observation based on your results will not change just because you used a slightly different input.
The test on Chapter 12 will be next Tuesday, the 25th.
We're finally back where we began, with inferences for proportions. You should complete your compare/contrast study guide (that you created from scratch) where you compare the formulas, language, and assumptions of each of the three chapters. The headings are z-procedures for means, t-procedures for means, and z-procedures for proportions. Know how to justify each of the formulas for standard deviations in the two-proportion inferences algebraically.
HW: Using the combined data from two sleeves of mini M&Ms (as you will find in the holiday section of the grocery store), test the null hypothesis P = 1/6, where p represents the true proportion of brown M&Ms (the best ones!). Perform the complete test, using PHANTOMS as a guide. For those who were absent, we're talking about the little tiny plastic sleeves of M&Ms that come in a blue bag (about 17 to the bag). There are around 50 M&Ms in each sleeve unless you get short-changed.
HW for Friday: 12.25, .26, and .28.
March Madness: post your NCAA men's basketball brackets at CBSSportsline with the Linnerstats bracket. The password for the bracket is just what you'd expect, gogators. If you are a bracket rookie, this means that you predict the winners of the 63 games in the NCAA basketball championship tournament. The software at CBSSportsline makes it really easy. You have to work fast. . . the brackets close soon.
HW for Thursday: Write up the inferences (hypothesis test and confidence interval) you generated today using the fluffy pom poms. Make your answers complete and correct. First period, please be prepared to meet me in our temporary location after our brief homeroom first thing Thursday.
HW due Wednesday: Complete write-up (PHANTOMS) of the Skittles hypothesis you generated in class. (Run a 1-proportion z-test on a large-enough sample of Skittles. The size of the sample depends on what you consider a "success.")
HW due Tuesday, March 18th: 12.13, 12.15, 12.16, 12.17. Please note: The answers in the back of the book for problem 13 used 0.33 as the value for 1/3. Obviously, this is not going to give you the "correct" answer. Please use 1/3 instead of their estimate and realize that your answers will be a little different from theirs, but yours will be correct! You can check your answers using the STAT TEST 1-PROP Z TEST on the calculator. The observation based on your results will not change just because you used a slightly different input.
The test on Chapter 12 will be next Tuesday, the 25th.
We're finally back where we began, with inferences for proportions. You should complete your compare/contrast study guide (that you created from scratch) where you compare the formulas, language, and assumptions of each of the three chapters. The headings are z-procedures for means, t-procedures for means, and z-procedures for proportions. Know how to justify each of the formulas for standard deviations in the two-proportion inferences algebraically.
HW: Using the combined data from two sleeves of mini M&Ms (as you will find in the holiday section of the grocery store), test the null hypothesis P = 1/6, where p represents the true proportion of brown M&Ms (the best ones!). Perform the complete test, using PHANTOMS as a guide. For those who were absent, we're talking about the little tiny plastic sleeves of M&Ms that come in a blue bag (about 17 to the bag). There are around 50 M&Ms in each sleeve unless you get short-changed.
Monday, March 10, 2008
Chapter 11 Statistical Inference Part II (t-procedures)
HW for Wednesday, March 12: Find 10 problems from chapter 11 that have not been assigned yet and complete them. If you find problems that you cannot do, mark those, but they do not count toward your ten. YOUR TEST IS THURSDAY.
HW due Tuesday, March 11: 11.31 and 11.32. Keep the data from today's class in your calculator so we can finish the process tomorrow. Remember, the test is Thursday.
HW due Thursday, March 6: 11.10, 11.15. 11.17
HW due Friday, March 7 (Coach Rinehimer's birthday!!!): 11.16. 11.19, 11.20, 11.27, 11.30 (These are all related!) Good job with the pasta and grip labs today. My hypotheses were that there were 104 pieces of pasta on average in a cup and that the difference between right and left hand squeeze strengths was 7 pounds on average. Your job was to (1) collect data, (2) perform a hypothesis test using your results, and (3) construct a confidence interval for the average or averge difference. EACH of you is responsible for knowing how to do all the steps of these investigations.
HW due Monday, March 10: 11.26, 11.28
Your test on Chapter 11 will be Thursday, March 13th.
Happy Centennial!!!
W.S. Gosset's paper (remember, the brewer who developed the t-distribution?)was published in Biometrika 100 years ago THIS MONTH!
A link to the paper (of course he did not publish online. . .).
HW due Tuesday, March 11: 11.31 and 11.32. Keep the data from today's class in your calculator so we can finish the process tomorrow. Remember, the test is Thursday.
HW due Thursday, March 6: 11.10, 11.15. 11.17
HW due Friday, March 7 (Coach Rinehimer's birthday!!!): 11.16. 11.19, 11.20, 11.27, 11.30 (These are all related!) Good job with the pasta and grip labs today. My hypotheses were that there were 104 pieces of pasta on average in a cup and that the difference between right and left hand squeeze strengths was 7 pounds on average. Your job was to (1) collect data, (2) perform a hypothesis test using your results, and (3) construct a confidence interval for the average or averge difference. EACH of you is responsible for knowing how to do all the steps of these investigations.
HW due Monday, March 10: 11.26, 11.28
Your test on Chapter 11 will be Thursday, March 13th.
Happy Centennial!!!
W.S. Gosset's paper (remember, the brewer who developed the t-distribution?)was published in Biometrika 100 years ago THIS MONTH!
A link to the paper (of course he did not publish online. . .).
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