  We start with the distinction of outcome- and belief-based Bayesian models of
the sequential update of agents' beliefs and subjective reliability of sources
(trust). We then focus on discussing the influential Bayesian model of
belief-based trust update by Eric Olsson, which models dichotomic events and
explicitly represents anti-reliability. After sketching some disastrous recent
results for this perhaps most promising model of belief update, we show new
simulation results for the temporal dynamics of learning belief with and
without trust update and with and without communication. The results seem to
shed at least a somewhat more positive light on the
communicating-and-trust-updating agents. This may be a light at the end of the
tunnel of belief-based models of trust updating, but the interpretation of the
clear findings is much less clear.
