 In some models staged in the ontological models framework, an ontic state \(\lambda\) is only compatible with preparation procedures associated with one specific quantum state \(\psi\). In that case, \(\psi\) can be seen as part of \(\lambda\) and, therefore, as an element of reality itself. Models of this type are referred to as “\(\psi\)-ontic”. In other models, an ontic state \(\lambda\) can be the result of preparation procedures associated with different quantum states \(\psi\). In these models, \(\psi\) is not an aspect of reality and is often more naturally seen as reflecting an agent’s incomplete knowledge about the underlying ontic state \(\lambda\). Models of this type are referred to as “\(\psi\)-epistemic”. Spekkens (2007) motivates the search for attractive \(\psi\)-epistemic models by pointing out various parallels between quantum mechanics and a toy model in which the analogue of the quantum state is epistemic in that it reflects incomplete information about an underlying ontic state.