Relating to or serving as a criterion; concerning or establishing standards used for judgment or evaluation.
From 'criterion' plus '-al' (relating to). This adjective form allows criterion to modify other nouns in describing things related to standards or judgment.
When scientists say a 'criterional approach,' they mean they're being systematic and standards-based—it's jargon for 'we thought this through carefully.'
Complete word intelligence in one call. Free tier — 50 lookups/day.