What might be the meaning of the phrase, 'make a difference' which you use in your writings? If there were 'more' 'expert' teachers, there would be more educated people. Would that really make that much of a difference?

The biggest issue we deal with when we start working with schools is to understand their concept of ‘impact’ – yes it must be more than test scores, surface level knowledge…This indeed is the first question for m[uch] which all follows. An educated person knows what to do when they do know what to do!” (John Hattie, personal communication, March 13, 2018).