A spike in attention directed toward a particular location may signal an important update, such as the need for aid for the location<cite> (Varga et al. 2013)</cite> . While collective attention is often measured with activity metrics such as post volume (Mitra, Wright, Copyright c 2020, Association for the Advancement of Artificial Intelligence (www.aaai.org). and Gilbert 2016), such metrics often focus on an aggregate quantity summary of attention without considering the nuanced content side of attention dynamics.