Note that the study looked at kids who took the PSAT in 10th and one or more AP tests in 11th, and kids who took the PSAT in 11th and one or more AP tests in 12th. It did not look at kids who took both the PSAT and an AP in 10th.
After reading (rather than skimming) the study, I see that you are correct -- thanks. The College Board has created an "AP Potential" tool based on the study where the probability of achieving an AP score >= 3 or >= 4 is shown as a function of PSAT score (either a sub-score or a composite, based on the AP exam score to be predicted). The stats for Calculus AB can be retrieved at http://www.collegeboard.com/counselors/app/expectancy.html?calcab
The College Board also has a report "AP Score Distributions for Specific Student score-Level Groups 2011" http://professionals.collegeboard.com/profdownload/AP-Score-Dist-by-Grade-Level-2011.pdf
showing average AP score by
grade level. Here are some of the numbers:
grade #scores avg_score %passing
<9 4283 2.91 59.72
9 74762 2.53 47.37
10 380206 2.81 56.75
11 1263768 2.94 60.06
12 1621118 2.84 57.66
>12 4159 3.43 72.81
There were only 4283 exams taken by students in grades before 9th, but their average score of 2.91 is about the same as the 2.94 of high school juniors. All students ought to take AP exams in 8th grade, since research shows that such students do as well as 11th and 12th graders
. But seriously, the numbers do show that the self-selected group of students who take AP exams before 9th grade do almost as well as 11th and 12th graders.
Unfortunately for gifted students, the College Board discourages taking AP classes before 9th grade, even writing "The AP label cannot be affixed to courses and transcripts prior to 9th grade." What if a school district allowed a gifted 8th grader to take AP calculus alongside 12-graders?http://apcentral.collegeboard.com/apc/public/repository/Appropriate-Grade-Levels-for-AP-Courses.pdf
Policy: Appropriate Grade Levels for AP Courses
The AP Program recognizes the autonomy of secondary schools and districts in setting AP course participation policies that best meet their studentsí unique needs and learning goals. At the same time, AP courses are specifically designed to provide challenging, college-level coursework for willing and academically prepared high school students. Student performance on AP Exams illustrate that in many cases AP courses are best positioned as part of a studentís 11th and 12th grade academic experience. Some subject areas, however, such as World History and European History, can be successfully offered to academically prepared 10th grade students.
Educators should be mindful of the following when considering offering AP to younger students. AP courses are rarely offered in 9th grade, and exam results show that, for the most part, 9th grade students are not sufficiently prepared to participate in a college-level course. Therefore, the College Board believes these students would be better served by coursework focusing on the academic building blocks necessary for later, successful enrollment in college-level courses. Many college admissions officers support this position, feeling that students should not be rushed into AP coursework, but should instead develop the necessary skills and conceptual understandings in foundational courses prior to enrolling in AP. AP coursework completed in 9th grade is not often deemed credible by the higher education community. The AP designation may only be applied to authorized courses offered at or above the 9th grade level which have received authorization through the annual AP Course Audit process. The AP label cannot be affixed to courses and transcripts prior to 9th grade. There is one exception to this policy: AP world language courses. These courses focus on linguistic proficiency and cultural competency, so in rare situations these courses can be successfully offered earlier than 9th grade among students who can already speak, read, and write the language with fluency. In summary, the AP Course Audit will only renew or authorize courses that are offered exclusively in grades 9-12, with the exception of AP world language programs.
The College Board recognizes that there are some occasions in which students may be prepared to take an AP Exam prior to 9th grade. Because students are not required to take an AP course before taking the AP Exam, schools may choose to administer AP Exams to students of any grade level, so long as the restriction against use of the AP label on courses and transcripts prior to 9th grade is observed.
In deciding when to offer college-level coursework to any student, educators should carefully review the curricular and resource requirements for each AP course, and consider whether a student has received the appropriate academic preparation. AP courses require students to apply advanced critical thinking and analytical skills that are typical of comparable college-level courses. This guiding AP enrollment policy holds true for all AP courses and exams, regardless of the grade level in which a school or district decides to offer AP coursework.