  Recently the field of Human-Robot Interaction gained popularity, due to the
wide range of possibilities of how robots can support humans during daily
tasks. One form of supportive robots are socially assistive robots which are
specifically built for communicating with humans, e.g., as service robots or
personal companions. As they understand humans through artificial intelligence,
these robots will at some point make wrong assumptions about the humans'
current state and give an unexpected response. In human-human conversations,
unexpected responses happen frequently. However, it is currently unclear how
such robots should act if they understand that the human did not expect their
response, or even showing the uncertainty of their response in the first place.
For this, we explore the different forms of potential uncertainties during
human-robot conversations and how humanoids can, through verbal and non-verbal
cues, communicate these uncertainties.
