(MONEY Magazine) – While other publications simply attempt to tell you which colleges are the strongest academically, we set out to identify the 150 best college buys--the schools that deliver the highest-quality education for the tuition they charge. This makes our ranking an excellent place to start your college search or to supplement information you obtain on your own from schools and from other guides.

Our value approach explains why our ranking includes such remarkably varied institutions as a nationally prestigious university, Caltech (No. 1), and a small midwestern public college, Missouri's Truman State University (No. 4). We aren't suggesting the schools are in the same league academically--they most certainly are not--but that the education they offer is well worth their tuition, $18,216 at Caltech and $5,516 at Truman. (We use out-of-state tuition for public schools to help people searching nationwide for college bargains.)

We based our analysis mostly on data compiled with the help of Wintergreen/Orchard House of New Orleans, a publisher of college directories. (We obtained some additional data from John Minter Associates of Boulder.) In our ranking, we analyzed 16 measures of educational quality, then compared them with each college's sticker-price tuition and fees to arrive at a value rating. Essentially, the schools that did best charge lower tuition than colleges of similar quality.

Our rankings include all four-year undergraduate schools that answered the Wintergreen/Orchard House and MONEY surveys, except for colleges with fewer than 250 students, fewer than three majors, part-time enrollments of more than 45% or no dormitories.

Here are the 16 factors analyzed in our study; we also give the national averages for the data we used and, where appropriate, name the schools in our top 100 that scored highest for each factor:

--Entrance examination results. We used the percentage of freshmen who entered college in the fall of 1995 with both verbal and math scores above 500 on the SAT (average percentage who did that well at all colleges: verbal 48%, math 61%) or above 23 on the composite ACT (average: 39%).

--Class rank. We looked at the percentage of entering freshmen who finished in either the top fifth (average: 43%) or the top quarter (48%) of their high school classes, depending on which statistic the colleges could supply.

--High school grade point average. Using the standard four-point scale, we considered the high school GPAs of the entering freshman class. Caltech had the highest average, 3.9, vs. the national average of 2.9.

--Faculty resources. We compared the number of full- and part-time undergraduates to the number of full- and part-time faculty. Caltech had the lowest ratio, 3 to 1, compared with the 14-to-1 average in our survey of 1,115 schools.

--Faculty quality. This is the ratio of students to faculty members who hold the highest degrees available in their fields. Caltech was tops with a 3-to-1 ratio; the national average is 19 to 1.

--Faculty deployment. We considered the ratio of students to tenured faculty who actually taught classes in the fall of 1995. Caltech had the best ratio, 6 to 1, vs. the 31-to-1 average.

--Library resources. We divided the total of all reference materials, including books, periodicals and microfilm, by the number of students using the campus libraries. Yale's huge 1,645-to-1 ratio dwarfed the 177-to-1 average.

--Instructional budget. We used Department of Education reports to calculate each school's expenditure per student. Caltech spent the most, $46,613; the average was $5,008.

--Student services budget. These are the dollars a school spends on services such as career guidance and student activities. Dartmouth spends $4,130 per student; the average was $1,209.

--Freshman retention rate. This is the percentage of 1994 freshmen who returned to each school in the fall of 1995. Yale scored best with 98%; the average was 75%. A high percentage indicates that students are happy with the education they are receiving. Also, colleges that score best on this measure tend to have the highest percentage of students who graduate within four years. Fully 89% of Yale's 1991 freshmen earned degrees in four years.

--Four-year graduation rates. This is the percentage of students who earn degrees in four years. The national average was 41%.

--Five- and six-year graduation rates. This is the percentage of freshmen who graduate within five (average: 52%) or six (average: 55%) years; few colleges track students' pursuit of a degree longer than six years. We used the five-year rate only when colleges couldn't provide the six-year rate.

--Advanced study. This is the percentage of students who went on to professional or graduate schools; national average: 21%.

--Default ratio on student loans. The percentage of students who default on their loans within two years of leaving school helps identify colleges whose graduates may not be well prepared for careers. Martin Luther College had no defaulters; the national average is 7.1%.

--Graduates who earn doctorates. The National Research Council supplied the number of graduates who went on to earn Ph.D.s between 1983 and 1992. University of California-Berkeley had the most: 3,640 or 18% of its graduates in those years.

--Business success. We used data from Standard & Poor's Register of Corporations, Directors and Executives, which lists more than 70,000 top executives who went to college. (Yale had the most graduates in the register, 822.)