How can I define my impact as a teacher?

“We use gains in test scores, we look at changes in artifacts of student work over time, we ask students about their progress and learning, and we use classroom observation of the impact on students.  No one does it alone, as it is the triangulation of multiple forms of evidence about impact --- AND it is all about the interpretations we make from this evidence and it is these interpretations that need critiquing and evaluating” (John Hattie, personal communication, August 19, 2018).