  Software bots fulfill an important role in collective software development,
and their adoption by developers promises increased productivity. Past research
has identified that bots that communicate too often can irritate developers,
which affects the utility of the bot. However, it is not clear what other
properties of human-bot collaboration affect developers' preferences, or what
impact these properties might have. The main idea of this paper is to explore
characteristics affecting developer preferences for interactions between humans
and bots, in the context of GitHub pull requests. We carried out an exploratory
sequential study with interviews and a subsequent vignette-based survey. We
find developers generally prefer bots that are personable but show little
autonomy, however, more experienced developers tend to prefer more autonomous
bots. Based on this empirical evidence, we recommend bot developers increase
configuration options for bots so that individual developers and projects can
configure bots to best align with their own preferences and project cultures.
