Mailing lists are a major communication channel for supporting developer coordina tion in open-source software projects. In a recent study, researchers explored tempo ral relationships (e.g., synchronization) between developer activities on source code
and on the mailing list, relying on simple heuristics of developer collaboration (e.g.,
co-editing fles) and developer communication (e.g., sending e-mails to the mailing
list). We propose two methods for studying synchronization between collaboration
and communication activities from a higher-level perspective, which captures the
complex activities and views of developers more precisely than the rather technical
perspective of previous work. On the one hand, we explore developer collaboration
at the level of features (not fles), which are higher-level concepts of the domain and
not mere technical artifacts. On the other hand, we lift the view of developer com munication from a message-based model, which treats each e-mail individually, to
a conversation-based model, which is semantically richer due to grouping e-mails
that represent conceptually related discussions. By means of an empirical study, we
investigate whether the diferent abstraction levels afect the observed relationship
between commit activity and e-mail communication using state-of-the-art time series analysis. For this purpose, we analyze a combined history of 40 years of data
for three highly active and widely deployed open-source projects: QEMU, BusyBox,
and OpenSSL. Overall, we found evidence that a higher-level view on the coordina tion of developers leads to identifying a stronger statistical dependence between the
technical activities of developers than a less abstract and rather technical view
