The term anecdata first began to appear in the early nineties and is a blend of the noun data and the adjective anecdotal meaning ‘based on personal experience rather than on facts that can be checked’. The adjective anecdotal dates back to the late 18th century, derived from the earlier noun anecdote (a short story told by someone about a real incident). The word data is classed as a mass noun in contemporary usage, but historically was the plural form of singular noun datum meaning ‘piece of information’. Mirroring this, there’s also some evidence for use of a singular form anecdatum, which identifies a single piece of information of this (anecdotal) type.

The term anecdata first began to appear in the early nineties and is a blend of the noun data and the adjective anecdotal meaning ‘based on personal experience rather than on facts that can be checked’. The adjective anecdotal dates back to the late 18th century, derived from the earlier noun anecdote (a short story told by someone about a real incident). The word data is classed as a mass noun in contemporary usage, but historically was the plural form of singular noun datum meaning ‘piece of information’. Mirroring this, there’s also some evidence for use of a singular form anecdatum, which identifies a single piece of information of this (anecdotal) type.