1. The multiple-choice answer sheets are scored by computer.
Each answer sheet is run through an electronic scanner. This transfers the information directly to cartridges, creating a record for that sheet. The scanning cartridge is processed by computer. The computer program checks each record for invalid or missing identification data and scores the student's responses.
The computer counts how many answers the student got wrong and then deducts a fraction of that number from the number of right answers. For exams with five-choice items, the fraction is one quarter; for those with four-choice items, it is one third. This type of scoring is appropriate for tests where students are not expected to have mastered all of the material that might be tested. With this procedure, the average multiple-choice score under purely random guessing is zero.
The total score is now rounded to the nearest whole number; if the score falls halfway between two whole numbers, it is rounded upward. If the student scores less than zero as a result of the correction for guessing, the score is replaced with a zero.
Finally, the computer creates a record for the student, containing his or her total multiple-choice score, and any subsection scores needed for calculating the composite score.
2. The free-response questions are scored at the annual AP Reading.
Unlike the multiple-choice section, which is scored by machine, the free-response section is scored by Readers at the annual AP Reading. To learn more about this unique gathering of college and university faculty and AP teachers, visit Scoring AP Exams.
3. The composite score is calculated.
For each AP Exam, there is a formula for combining the scores for the multiple-choice and free-response sections or subsections into a maximum weighted score (composite score). Once the weights have been decided and the free-response section scored, computing each student's composite score is a purely mechanical process and is done by computer.
Deciding on the cut-off point between each of the five scores is not a simple process. The statistical processes of equating and scaling are used to make adjustments to the cut-off scores each year. These adjusted cut-off scores are presented to the Chief Readers along with other information about the students' performance on the exam. The Chief Reader then makes the final decision about the four cut-off scores which determine the five AP Exam scores.