Presentation on theme: "AP Exam Development and Grading"— Presentation transcript:
1AP Exam Development and Grading The AP Physics exams are developed by a committee of high school and college physics facultyAfter the exams are administered, they are sent to Colorado State University where high school physics faculty set the rubrics and grade the exams.The Chief Reader and the staff of ETS set the points for student stores
2Recent AP Physics Exams AP Physics B (2010)70 multiple choice questions in 90 min (90 pts)2 long free response questions and (15 pts)5 short free response questions in 90 min (10 pts)180 minutes total points (scaled to 180)
3Recent AP Physics Exams AP Physics C (2010)Mechanics 35 multiple choice questions in 45 min (45 pts)3 free response questions in (45 min)Electricity and Magnetism35 multiple choice questions in 45 min (45 pts)Two 90 minute exams, 90 pts eachCalculators and a provided formula sheet will only be alowed on the free response portions of the B and C exams.
4AP Exam Development and Grading Scores are awarded to students based on the following scale:5 = student is well qualified to receive college credit for the course4 = student is well qualified to receive college credit for the course3 = student is qualified to receive college credit for the course2= student is possibly qualified to receive college credit for the course1 = no recommendation
5AP Scores Score Phys B Phys C - Mech Phys C – E & M 5 59-100 % %%446-58 %48-60 %39-53 %330-45 %36-47 %29-38 %222-29 %23-35 %16-28%10-21 %0-22 %0-15%
6Free-Response Questions Computational QuestionsInvolve solving a problem to produce a numerical answer.Partial credit is awarded if part of the answer is correct. Often, answers to one part of a question must be used to solve the next part of the question. Exam readers take this into account, but the student must show all of the steps to receive credit. If they make a mathematical error in the first part of a question, it may make getting a numerically accurate answer for the other parts impossible. By showing their equations and reasoning, the students can be awardedpoints for those subsequent parts.Merely writing relevant equations is insufficient for credit, since the tables of equations are provided.
7Free-Response Questions Derivation QuestionsInvolve solving a problem by manipulating variables to give the answer in an equation form.These questions often indicate which variables should be included in the final answer.Again, it is important that every step is clearly shown.
8Free-Response Questions Lab-Based QuestionsThese questions may ask students to design an experiment, analyze data, identify sources of error and/or draw conclusions and suggest ways to improve experiments.The best way to prepare the students for this type of questions is to conduct meaningful laboratory work throughout the course.
9Free-Response Questions Special attention should be paid to directive words and phrases when reading the questions and only provide the information required by these terms:"Justify" and "explain" call for an answer supported by prose, equations, calculations, diagrams, or graphs. The prose or equations may refer to fundamental ideas or relations in physics, such as Newton's laws, conservation of energy, Gauss' law, or Bernoulli's equation. In other cases, the justification or explanation may take the form of analyzing the behavior of an equation for large or small values of a variable in the equation.
10Free-Response Questions "Calculate" means that students are expected to show work leading to a final answer, which may be algebraic, but which is more often numerical."What is" and "determine" indicate that students do not need to show their work to obtain full credit. But, showing work leading to answers is a good idea because partial credit can be earned in the case of an incorrect answer."Derive" is more specific and indicates that students need to begin their solution with one or more fundamental equations, such as those given on the AP Physics Exam equation sheet. The final answer, usually algebraic, is then obtained through the appropriate use of mathematics.
11Solving the problem includes: 4. Equation (always solve for unknown)Write the relevant equation or equations that will allow you to solve for the unknown. Be sure to always solve the equation for the unknown instead of just a 'plug and chug' approach.5. SubstitutionOnce you have solved the equation algebraically, substitute the appropriate values.6. Answer with UnitsWrite down the answer with the appropriate units.Remember that 'naked' numbers make no sense in Physics!
127. Check the Answer Ask yourself: - Does my solution answer the question that was asked?Make sure that you have addressed all parts of the question and clearly written down your solutions.- Does my answer have the correct units and number of significant figures? 3Does the value I computed make physical sense? - Can I estimate what the answer should be to check my solution?- Does my final solution make sense in the context of the material I'm learning?
13Exam Tips - In General1) The test is designed to score one point per minute on average. Thus, you should plan on spending on average a little over a minute on each multiple-choice question, and fifteen minutes on a 15-point problem.2) If you can average a raw score of about 60% on the multiple-choice and free response portions of the exam, you’re on track to score a 5 on the exam. A raw score of about 45% may earn a 4, and 30% or so may earn a 3. (Although this may be a little higher this year due to no penalty for guessing affecting the statistics)
14Exam Tips - Multiple Choice 1) Read through all of the multiple-choice questions first, answering the ones you can quickly answer first, skipping those you need to come back to. Then go back and work out the questions which are more difficult for you.2) There is no penalty for random guessing so come back to each question.3) Eliminate questions that contain equations in which the units are not correct (like F = mv2). If the question is asking for force, for example, and the equation in the answer gives you units for energy, you can eliminate that answer.4) If two answers are close in wording, but contain opposite ideas, there is a reasonable chance that one of them is correct. By the same token, if two answers mean basically the same thing, they cannot both be correct, and you can eliminate them.5) Predict the answer before reading the answer choices so you aren’t tempted by wrong answers
15Exam Tips - Free Response 1) On the free response portion of the exam, read all of the questions and work the ones you’re most comfortable with first. The first question on the exam may not be the easiest one.2) Show enough work on each part to earn partial credit if you get the answer wrong. Even if a question calls for a one-word answer (like yes or no), write a few words about how you arrived at the answer. For example, “The current is clockwise by Lenz’s law” instead of just “clockwise” may get one extra point if “clockwise” is the wrong answer.3) If you’re not sure how to answer part of a free response question, at least write down a law or equation that you know is relevant (like “conservation of energy” or “Fnet = ma”). Often you’ll be given a point or two just for stating a relevant law.
16Exam Tips - Free Response 4) If you don’t know how to work part (a) in a problem, but need the answer to part (a) in part (b), make up an answer to part (a) and use it consistently throughout the rest of the problem. You will be given full credit for later parts even though part (a) is not correct.5) Your goal throughout the test should be to earn points, not worry about how many points you are losing. You don’t have to ace the test to get a good score since the grades are curved. Try not to get frustrated or discouraged while taking the test. Thousands of students around the world are frustrated and discouraged on test day, and it’s very likely that you are doing much better than you think you are.6) Don’t just try to compute answers, think! Good luck!
17• Verbal Descriptions • Pictures • Graphs • Mathematical TYPES OF MULTIPLE REPRESENTATIONS:• Verbal Descriptions• Pictures• Graphs• Mathematical• Motion Diagrams• Free Body Diagrams• Energy Bar Charts• Field Line Diagrams• Electrical Circuit Diagrams• Ray Diagrams• Energy States Diagrams