This study compares the explanatory power of the 2000 edition of Carnegie Classification, the 2005 revision of the classification, and selected variables underlying Carnegie's expanded 2005 classification system using data from the National Survey of Student Engagement's spring 2004 administration. Results indicate that the 2000 and 2005 classifications generally offer comparable explanatory power for measures of self-reported gains and student engagement, but the new variables from the 2005 system are more strongly related to cognitive outcomes and engagement than were the two categorical groupings. The variables most consistently related to outcomes and engagement are graduate-undergraduate coexistence, residential character of the campus, and arts and sciences share of undergraduate majors. Implications of the findings for research and assessment are discussed.