“We had very little transparency into student learning, we had very little transparency into the achievement gap, who is being left behind, who is getting hurt the most,” Michael Horn, Lexington resident and professor at the Harvard Graduate School of Education, said about measuring students’ learning before the Education Reform Act. “We take data for granted in today’s world — we’re going to be flying much blinder.”

Without requiring students to meet a standardized graduation benchmark, there is no longer a  “common measure” to determine what passing a grade means in Massachusetts, Horn said. By leaving those decisions up to districts, Horn worries the quality of education in marginalized communities will worsen.

“We know grade inflation is already rampant across the state and the country and increasingly decoupled from what objective measures tell us,” Horn, who has published several books on the future of education, said. “How much wider does that gulf get in years ahead?”