Schools that top Kiplinger's 50 Best Values in Public Colleges are noteworthy for their combination of top-flight academics and affordable costs. Our emphasis on academic strength is reflected in our scoring, academic quality measurements carry more weight than costs (almost two-thirds of the total). We also used academic-quality scores and average debt at graduation figures to break ties.

The rankings are based on data that more than 500 public four-year colleges and universities provided to Peterson's, a Nelnet company. We supplemented Peterson's data with our own reporting.

This is an update on our top 50 public schools. Our rankings are based on several measures of academic quality, including:

• Percentage of the 2005-06 freshman class scoring 600 or higher on the verbal and math components of the SAT (or scoring 24 or higher on the ACT)
• Admission rates
• Freshman retention rates
• Student-faculty ratios
• Four- and six-year graduation rates, which most schools reported for the student cohort entering in 1999

Then we ranked each school based on cost and financial aid. We looked at:

• Total cost for in-state students for the 2006-07 school year (tuition, mandatory fees, room and board, and estimated expenses for books)
• Average cost for a student with need after subtracting grants (but not loans)
• Average cost for a student without need after subtracting non-need-based grants
• Average percentage of need met by aid (need-based assistance)
• Average debt a student accumulates before graduation

We were looking for schools that were academically strong as well as affordable, so in our scoring, academic quality carries more weight than costs (almost two-thirds of the total). We used academic-quality scores and average debt at graduation to break ties.

Not included in our list

Our rankings focus on traditional four-year public universities with broad-based curriculums. Unfortunately, that meant we had to leave out some excellent schools with special programs, including military schools and service academies, schools that do not provide housing (their costs could not be compared with other colleges), schools with limited curriculum and private or partially private institutions.