PHY138Y - Mechanics - Quiz Results

The quizzes have been marked. You may determine your mark either via STORM at:
http://www.storm.utoronto.ca/PHY138Y1Y/student/
or in hardcopy form on the course bulletin board. The bulletin board is located on the West wall of the first floor of the North Wing of McLennan.

Report any problems with your quiz mark to Dr. Savaria in MP901A immediately.

You may see the three different quizzes, including the answers, with the links to the right. All are in pdf format.

Wednesday

Thursday

Friday

Raw Quiz Marks

We were very pleased with the results of the quiz. Here are some statistics:

Wednesday

Average	73.2
Standard Deviation	18.6
Median	81

Thursday

Average	89.6
Standard Deviation	15.7
Median	100

Friday

Average	78.6
Standard Deviation	21.5
Median	81

The results for the Wednesday and Friday tutorial quizzes are somewhat higher than we expected, which makes us happy. However, the Thursday marks are very very high. This is because Dr. Savaria, Professor Key and I all thought that Question 6 on that quiz would be much harder than it turned out to be.

Adjusting the Marks

Obviously, we have had to adjust the quiz marks so that the overall distributions, averages, etc. are the same for all three versions. Thus we have raised the marks for the Wednesday and Friday tutorials.

The marks for the Thursday quiz have not been adjusted.

These adjusted marks are the ones that will count towards your final mark in PHY138. They are the ones recorded in STORM.

The remainder of this section discusses the details of how the adjustment was done.

We define "breakpoints", which are raw marks that will be mapped into the adjusted marks. Raw marks between the breakpoints are scaled linearly. Here are the breakpoints that we used:

Wednesday Raw Mark	Friday Raw Mark	Mapped To:
0	0	0
42	43	50
43	44	60
44	45	70
45	46	80
100	100	100

The figure to the right indicates the mapping from Raw to Adjusted marks.

Although the mapping is somewhat different for the Wednesday and Friday quizzes, the graphs look almost identical.

Final Statistics

After adjustment, here is some information on the quiz marks. The differences between the three quizzes are as negligible as we could make them.

Mean	88.5
Standard Deviation	15.8
Median	93

About the Test

The main purposes for giving the quizzes were to:

Get students to study the material covered so far in class well in advance of the Test.
Give examples of the sorts of multiple-choice questions that will be a component of the Test.
Provide us with some feedback on how you are doing.

The fact that, with the exception of the surprisingly easy question on the Thursday quiz, students did somewhat better than we had anticipated pleases us.

You should be aware, however, that on the Test we will be trying to achieve a more "normal" grade distribution. The definition of a normal grade distribution at the University of Toronto has:

An average close to 70%.
About 15% to 20% of the class receiving a mark of 80 or better.
5% or less of the class receiving a mark less than 50.
Roughly equal numbers of B's and C's.

A few students did not do too well on the quiz. But the fact that most students exceeded our expectations I attribute to the fact that this is a really good group of students. You, however, are free to think that instead it is due to the quality of the lectures.