When colleges look to compare themselves with others, they are not much different from high-school students chasing popularity: Everyone wants to be friends with the Ivy League, but the Ivy League is really picky about whom it hangs out with. Each year colleges submit "comparison groups" to the U.S. Department of Education to get feedback on how their institution stacks up in terms of finances, enrollment, and other measures tabulated in the Integrated Postsecondary Education Data System. The groups sometimes represent a college's actual peers but more often reveal their aspirations. "The Chronicle" analyzed the relationships of nearly 1,600 four-year colleges that make up those groups to map out the power players in higher education. The typical college selected a comparison group of 16 colleges with a higher average SAT score and graduation rate than its own, lower acceptance rate, and larger endowment, budget, and enrollment. The eight Ivy League colleges among them chose only 12 institutions outside their own number as peers. Institutional-research officers acknowledge that their institutions' comparison groups often include desired peers that are not true peers. Colleges want to receive data reports on enrollments, graduation rates, student costs, faculty, and budgets for institutions they aspire to be more like.