What are the most expensive colleges? That depends what you mean by "most expensive." Are they the schools with the highest listed tuition — the highest sticker price? Or those with the highest average net price — what the typical student pays to attend after accounting for all expenses, but also all financial aid? What about different types of schools? Is it fair to compare public and private colleges?

Because there's no simple answer, under a 2008 law the Department of Education publishes different lists, and on Thursday released its latest annual update. Here are the top five in some of the main categories. The data are for 2011-2012.

Public four-year colleges with highest tuition, in-state

1. University of Pittsburgh-Pittsburgh Campus $16,132

2. Pennsylvania State University — Main Campus $15,984

3. University of New Hampshire — Main Campus $15,250

4. University of Vermont $14,784

5. Colorado School of Mines $14,453

Private (not-for-profit) four-year colleges with highest tuition

1. Columbia University (N.Y.) $45,290

2. Sarah Lawrence College (N.Y.) $45,212

3. Vassar College (N.Y.) $44,705

4. George Washington University (District of Columbia) $44,148

5. Trinity College (Conn.) $44,070

Public four-year colleges with highest net price, in-state

1. Miami University-Oxford (Ohio) $22,210

2. Pennsylvania State University — Main Campus $21,342

3. University of Guam $21,296

4. St. Mary's College of Maryland $20,521

5. Pennsylvania State University — Altoona $20,457

Private (not-for-profit) four-year colleges with highest net prices

1. School of the Art Institute of Chicago $42,882

2. Ringling College of Art and Design (Fla.) $40,222

3. The Boston Conservatory $39,602

4. Berklee College of Music (Mass.) $38,814

5. California Institute of the Arts $38,802