"Confirmatory evidence" refers to information or proof that supports or verifies something that has been claimed or suggested. It provides additional support to make sure an idea or statement is true or accurate. Full definition
Add to those propensities the confirmation bias (which seeks and finds confirmatory evidence for what we already believe) and the hindsight bias (which tailors after - the - fact explanations to what we already know happened), and we have the foundation for conspiratorial cognition. (scientificamerican.com)
This surety is called the confirmation bias, whereby we seek and find confirmatory evidence in support of already existing beliefs and ignore or reinterpret disconfirmatory evidence. (scientificamerican.com)
Look for confirmatory evidence from other indicators of achievement including student work samples, performance assessments, other standardized tests, and the like. (aft.org)