If 'true', this attribute indicates that the statistical characterisation of a SimDM/Propertyis aPriori. That is it indicates that the value says something about what the publisher believes are the possible values the SimDM/Property can assume. An "p priori" characterisation is therefore a translation of the effects that the input configuration (SimDM/ParameterSetting, SimDM/InputDataset), the  "provenance-of-the-actual-experiment" therefore) is EXPECTED to have on the final result, represented by the SimDM/OutputDataset-s and the SimDM/Property-s of their constituent objects.

Alternatively, if the value is "false", it indicates that the statistical charecterisation is 'a posteriori', i.e. it says something about the actual values that were assumed. This requires in general some level of post processing beyond simply storing the result, but in general using simple statistics such as mean and standard deviation that are not modelled as a separate SimDM/Experiment.