Causal reasoning under ambiguity requires subjects to estimate
and evaluate ambiguous observations. This paper proposes a
hierarchical model that accounts for the uncertainty of both the
distribution of the functional form selection and distribution of
the ambiguity treatment selection. The posterior distribution of
the causal estimates is determined by both the functional form
and the ambiguity processing strategy adopted by the reasoner.
A model is tested in a simulation study for its ability to recover
the strategy and functional form adopted by subjects across a
range of hypothetical conditions. The model is further applied
to the results of an experimental study.