Evidence must meet minimum standards to be considered evidence.

To be con­sid­ered evi­dence, the assumption/hypothesized rela­tion­ship that you are seek­ing evi­dence for must have been mea­sured or observed. Opin­ions that some­thing should work, even when con­tained in a peer reviewed paper, do not count. For exam­ple, if sus­tain­abil­i­ty stan­dards are expect­ed to change cor­po­rate behav­ior, then exam­ples where sus­tain­abil­i­ty stan­dards were fol­lowed by wide­spread adop­tion across the indus­try would be required to con­sti­tute evi­dence. All knowl­edge sources have the poten­tial to hold evi­dence for our assump­tions — not just peer reviewed lit­er­a­ture. The prac­ti­tion­er’s job is to dis­cern whether a quan­ti­ta­tive or qual­i­ta­tive assess­ment from any source deals with an obser­va­tion of the assump­tion being true or false (evi­dence) or states its poten­tial (not evidence).