Here are two definitions of evidence i came across via Google that i think support the concept of Evidence Based Enterprise Architecture.

‘evidence is factual knowledge or data that lends support to or casts doubt on a hypothesis. It is information on which we base our beliefs and ideas of how the world works.’ Morris (2004)

‘It is information or data that people select to help them answer questions… Evidence is anything that can be used as evidence to answer questions …One person’s evidence is another’s information’ Knight 2004