By Jane Bennett Clark, Senior Editor October 24, 2011 After ranking colleges and universities for more than ten years, we've tweaked our formula and our presentation for a sharper focus on our long-standing theme -- value. Here's how we divvy up the criteria that determine our rankings to give you our best assessment of quality and affordability. (For a deep dive into the measure of our rankings, check out our sortable data tables.)SEE OUR TOOL: Get Complete Rankings of Our Top 200 Private Universities and Liberal Arts Colleges COST AND FINANCIAL AID: 31.25% Recognizing that every family benefits from a low sticker price, we give the most points to schools with the lowest total cost (tuition, fees, room and board, and books). We bestow points in equal measure on schools that reduce the price through need-based aid and those that knock the price down through non-need-based aid. Some schools fail to cover the gap between expected family contribution and the aid they provide. We reward schools with the highest percent of need met. To cover our bases, we give points up to the same maximum to schools based on the percent of non-need-based aid given to students. Advertisement COMPETITIVENESS: 25% We include test scores in our formula because strong students attract other strong students, and their synergy creates an intellectual sizzle that enhances education. Admission rate, the percentage of students accepted out of those who apply, demonstrates the college's selectiveness in choosing among candidates. Because more students are applying to more schools, we added yield to our list of criteria. That number -- the percentage of students who enroll out of those who are admitted -- shows the college’s ability not only to attract strong students but also to close the deal. ACADEMIC SUPPORT: 12.5% Small classes, individual attention and academic mentoring contribute to student success. The students per faculty figure measures whether the college has the personnel to deliver on all three. Freshman retention rate shows the percentage of first-year students who return for sophomore year rather than dropping out or transferring. Retention rate is an important indicator of how happy students are with their education and how well the college supports them on their path to a degree. Advertisement GRADUATION RATES: 18.75% Paying for four years of college is tough enough. Paying for five or six? Do the math and weep. Our retooled rankings give maximum weight to the four-year graduation rate to reward colleges that help students get undergraduate degrees on time and within budget. Because we know that life happens, we also give points -- albeit half as many -- to colleges with a strong showing of students who get the job done in five years. STUDENT INDEBTEDNESS: 12.5% As college costs rise, so does average debt at graduation, to the tune of $24,000 among all student borrowers and $28,000 for student borrowers at private colleges, according to the Project on Student Debt. We think that's a lot, so we bumped up our points to benefit colleges that keep average debt down. We also created a new category: percent of students who borrow; the lower the number, the better the score.