WORCESTER, Mass. – Data-crunching scholars have confirmed what education reform advocates have long believed: Students who study under great teachers learn more than those who study under mediocre ones.

That conclusion came this week after scholars studied the relationship between a teacher’s evaluation rating and how well his or her student performed on Massachusetts’ standardized test.

Telegram.com explains: Using teacher evaluation data from the 2012-13 school year – culled from 213 Massachusetts school districts – researchers matched it with their students’ “student growth” rating, as determined by their performance on the state assessments.

MORE NEWS: From Classroom to Consulate Chef: Culinary Student Lands Dream Job at U.S. Embassy in Paris

That “student growth” rating (known as a student growth percentile) is computed by comparing one student’s progress on the state test to the progress of other students with similar scores.

Telegram.com puts it this way: “In other words, how is a student progressing and how does this compare with his or her peers?”

Consider the results for Worcester Public Schools:

Worcester teachers who were rated “exemplary” under the state’s teacher evaluation system “had an average (student growth percentile) of 55.3 in English and 57.6 percent in math; those figures at the state level are 56.7 and 58.3 percent, respectively,” Telegram.com reports.

“Students of teachers rated ‘needs improvement’ in Worcester had an average median (student growth percentile) of 42.1 in English and 41.9 in math; those figures at the state level are 44.7 and 46.8, respectively,” the news site reports.

While Worcester teachers in both the “exemplary” and “needs improvement” categories fell shy of the state averages in terms of student growth, the “big picture” takeaway of this analysis is that students with high-performing teachers show bigger learning gains than those with struggling teachers.

MORE NEWS: Know These Before Moving From Cyprus To The UK

(Readers are encouraged to access the Telegram.com article for all the technical details surrounding this analysis.)

The ramifications of this study are significant. Not only does it seem to validate the results of Massachusetts’ teacher evaluation system (which has been in place since 2011), but it also knocks down teacher unions’ long-standing argument that educators are interchangeable and, therefore, should have their pay and job protections determined by their seniority, not the quality of their work.

We look forward to seeing the results of similar studies from other states. If they turn out as positively as Massachusetts’ early study has, if will provide research-based affirmation of the many common sense policy proposals put forward by the education reform movement.