In this theoretical paper, we delineate two fundamental paradigms in how scholars conceptualize the nature of machines in human-machine communication (HMC). In addition
to the well-known Media Equation paradigm, we distinguish the Media Evocation paradigm. The Media Equation paradigm entails that people respond to machines as if they
are humans, whereas the Media Evocation paradigm conceptualizes machines as objects
that can evoke reflections about ontological categories. For each paradigm, we present
the main propositions, research methodologies, and current challenges. We conclude with
theoretical implications on how to integrate the two paradigms, and with a call for mixedmethod research that includes innovative data analyses and that takes ontological classifications into account when explaining social responses to machines.