What Is the Common Data Set (and Why You Can Trust It)?
The short answer
The Common Data Set (CDS) is a standardized report that nearly every U.S. college publishes about itself once a year. It uses the same questions and the same numbered sections at every school, so a figure you read for one college means the same thing at the next. When we tell you a target SAT Math score for a given university, the number comes from one specific line of that school's CDS: Section C9, which reports the 25th and 75th percentile test scores of its enrolled first-year class. That makes the CDS a primary source. The school is reporting on itself, in a fixed format, in public.
Who is behind it
The CDS is produced through the Common Data Set Initiative, a collaboration among the higher-education community and three publishers: the College Board, Peterson's, and U.S. News & World Report (Common Data Set Initiative). The point of the collaboration is to agree on one shared questionnaire so colleges answer the same questions the same way, which improves how comparable the numbers are across institutions and reduces how many separate surveys each school has to fill out.
Cornell describes its own CDS plainly: it is a standardized questionnaire developed through collaboration among colleges and universities, meant "to improve the comparability of data reported across institutions" (Cornell Institutional Research and Planning). Cornell, like most schools, posts its filings going back many years in both PDF and spreadsheet form.
What the sections cover
The CDS is organized into ten lettered sections, A through J:
| Section | Covers |
|---|---|
| A | General institutional information |
| B | Enrollment and persistence |
| C | First-year admissions, including test scores |
| D | Transfer admissions |
| E to J | Academics, student life, costs, financial aid, faculty, degrees conferred |
For applicants, Section C is the one that matters, and within it, item C9 is where standardized test scores live. C9 reports the 25th percentile and the 75th percentile SAT and ACT scores for students who actually enrolled.
How to read the percentiles
A percentile here describes the enrolled class, not your odds. If a school reports an SAT Math 25th percentile of 760, that means 25 percent of its enrolled first-year students scored 760 or below in Math, and 75 percent scored at or above it. The 25th-to-75th range is sometimes called the middle 50 percent: half the class sits inside it.
That framing is why the 25th percentile is the most useful single number for setting a target. Land at or above it and you are inside the range where a quarter of admitted-and-enrolled students already are, on that one measure. It is a floor to clear, not a guarantee, because admissions weighs far more than a test score.
The Ivy League SAT Math floors are tightly bunched at the top of the scale. Across the eight schools, the Section C9 SAT Math 25th percentiles run from 720 at Dartmouth up to 770 at Harvard, Columbia, Penn, and Cornell, with Princeton at 760, Yale at 740, and Brown at 730. We walk through every school in What SAT Math Score Do You Need for the Ivy League?.
Where these scores sit nationally
A 770 in SAT Math is near the very top of the 200 to 800 scale, and it sits at or above the 25th-percentile floor of every Ivy. For context on the rest of the range, the College Board's Nationally Representative percentiles (which compare a score against all U.S. students of that age, not just test takers) place an SAT Math score of 510 at the 52nd percentile and 650 at the 90th percentile (College Board, Understanding SAT Scores). So the most selective schools are drawing their enrolled classes from well above the 90th-percentile band in Math. We unpack how these two different percentile systems work, and why they give different numbers, in SAT Math Percentiles, Explained.
Why we trust it
Three properties make the CDS the right source for an honest target:
- It is self-published by each school, on the school's own institutional-research pages, not filtered through a ranking or a marketing brochure.
- It is standardized, so C9 means the same thing everywhere and the numbers are genuinely comparable.
- It is updated yearly, so you can read the most recent class rather than an old average.
When a college-prep claim cites a "needed" score, ask where the number came from. If the answer is a specific year's Section C9, you can check it yourself in minutes. That is the standard we hold ourselves to: every score target we publish traces back to a school's own Common Data Set, by name and by year.