Ideally the "real world" truth is established through primary research. However, as this is often not practical, it is common to use 3rd party reference data from sources which are deemed trustworthy and of the same chronology
Ideally the "real world" truth is established through primary research.However, as this is often not practical, it is common to use 3rd party referencedata from sources which are deemed trustworthy and of the same chronology