Scoring the AP Physics-C Exams by sparkunder21

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									Scoring the                                  The RAW score on each MC section is
                                             converted to a score by multiplying by
AP Physics-C Exams                           the appropriate factor to scale it up to the
                                             45 points allotted to each section. If no
The AP Physics-C exam has two parts          questions were eliminated the factor is
and each part is graded and reported
separately. These are known as the           45/35 = 1.2857          Therefore, on that
                                                                     section only
a) Mechanics (Mech),
                                             MC Score = RAW • 1.2857
and
                                             Sometimes a question is eliminated from
b) Electricity and Magnetism (E&M)           the scoring. This might occur because of
                                             an ambiguity in a question or in one of
exams.                                       its possible answers. Sometimes the
                                             reason is highly technical and comes out
Each exam consists of two parts. These       of the analysis of the response profiles of
are known as the Multiple-Choice (MC)        the questions.
and Free-Response (FR) sections of the
exam.                                        If, in a given year, one questions is
                                             eliminated from a MC section, then for
Multiple-Choice Sections                     that section only, the factor is

Calculators may not be used during the       45/34 = 1.3235          Therefore, on that
MC sections of these exams.                                          section only

The multiple-choice sections are given       MC Score = RAW • 1.3235
first and consecutively. Each MC exam
is timed separately. Students may not        Free-Response Sections
return to the earlier section. Calculators
are not allowed during the MC sections       Calculators may be used, but not shared,
of the two exams. In truth, calculators      during the FR sections of these exams.
would not be much help even if they
were allowed. Each MC section lasts          The FR section of each exam consists of
forty-five minutes.                          three questions and each question is
                                             worth 15 pts. The FR section of each
Each MC exam consists of 35 questions        exam is thus worth 45 points.
and is worth a maximum of 45 points.
There is a penalty for wrong answers.        All questions in the FR sections have
The raw score is computed as the             multiple sub-parts. The point
number of right answers minus one-           distribution among the sub-parts is not
quarter of the number of wrong answers.      listed on the exam. Each sub-part of a
                                             question will be assigned a point value
RAW score = #right – ¼ • #wrong              but the points are not necessarily
                                             distributed equally among the sub-parts.
Composite Scores                           Example Calculations
The composite score for each exam is       Mech MC exam results – 35 questions
the sum of the unrounded scores from             #right = 28
the corresponding MC and FR sections.            #wrong = 6
                                                         1 question unanswered
Composite score = MC score + FR score
                                            Mech MC Score =
The composite score is rounded to the             (28–6/4)•1.2857 = 34.07105
nearest integer.
                                           E&M MC exam results – 34 questions
Grades                                          #right = 25
                                                #wrong = 7
The Chief Faculty Consultant sets the
                                                        2 questions unanswered
cut points within the total of 90 points
available on each exam. The cut points
divide all the composite scores into        E&M MC Score =
Grades on a 1 to 5 scale. The cut points         (25-7/4) •1.3235 = 30.771375
vary from year to year, so definitive
values cannot be given.                    Mech FR exam results
                                                 Q1 = 11
As examples, however, The College                Q2 = 7
Board reports the following cut points           Q3 = 3
for the 1998 AP Physics C exams.
                                            Mech FR Score = 11 + 7 + 3 = 21
AP Physics C – Mechanics
                                           E&M FR exam results
    Composite               Grade               Q1 = 10
   Score Range                                  Q2 = 5
     55 – 90                  5                 Q3 = 4
     43 – 54                  4
     32 – 42                  3             E&M FR Score = 10 + 5 + 4 = 19
     21 – 31                  2
      0 - 20                  1            Then using the 1998 cut points for this
                                           example, we get
AP Physics C – E & M

    Composite               Grade           Mech Composite Score = 55.07105 = 55
   Score Range
     49 – 90                  5             E&M Composite Score= 49.771375 = 50
     35 – 48                  4
     26 – 34                  3             1998 Mech Grade = 5
     15 – 25                  2
      0 - 14                  1             1998 E&M Grade = 5

								
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