The phrase "tangible evidence" refers to physical proof that can be seen, touched, or felt, serving as confirmation of something's existence or occurrence. Full definition
Because this gives them some kind of tangible evidence of their staff's achievements backed by official certification. (elearningindustry.com)
This level of focus grounds the professional learning conversation by providing tangible evidence for and path toward the necessary changes in practice. (auslchicago.org)
Until you have tangible evidence for the existence of god, the notion of god remains in the realm of ideas. (religion.blogs.cnn.com)