  North American institutions of higher education (IHEs): universities, 4- and
2-year colleges, and trade schools -- are heavily present and followed on
Twitter. An IHE Twitter account, on average, has 20,000 subscribers. Many of
them follow more than one IHE, making it possible to construct an IHE network,
based on the number of co-followers. In this paper, we explore the structure of
a network of 1,435 IHEs on Twitter. We discovered significant correlations
between the network attributes: various centralities and clustering
coefficients -- and IHEs' attributes, such as enrollment, tuition, and
religious/racial/gender affiliations. We uncovered the community structure of
the network linked to homophily -- such that similar followers follow similar
colleges. Additionally, we analyzed the followers' self-descriptions and
identified twelve overlapping topics that can be traced to the followers' group
identities.
