But first a warning: prepare for a big mood swing.

After all, in the early years of MCAS testing, the results had been mixed to disappointing. In the first two years of the MCAS, at least 52 percent failed the math exam. In the last year before that test began counting, the failure rate was 45 percent.

English scores tell a similar story. In the first three years, when the exam didn’t matter, the pass rate never exceeded 72 percent. In fact, it had fallen to 66 percent in 2000.

So when MCAS began to matter, many prepared for the worst. Okay, ready? Here are the first paragraphs of the history of the globe about the results published that day.

“The state yesterday released 2001 MCAS results, showing that the number of 10th graders who failed the exam has dropped by nearly half – a striking shift that is sure to transform the years-long debate over the exam. standardized”.

“Interim Governor Jane M. Swift, flanked by delighted lawmakers and education officials in the House of Representatives, announced that 82 percent of 10th graders passed English, up from 66 percent in 2000. The pass rate in math was 75 percent , compared to 55 percent in 2000.”

Education officials were understandably elated. They and academic testing experts attributed the big jump in scores to the fact that test takers had understood that the test had consequences.

It was a particularly good day for Swift, who had strongly supported the graduation exam despite waves of pessimism, and for then-Commissioner of Education. David P. Driscoll, who had predicted that the scores would increase once the test was put into play. Driscoll attributed the students’ increased effort to “a major factor” in the increase in passing scores.

So what happened? One possible (although highly implausible) explanation for the big jump is that students were simply taking the exam more seriously after 2001, but they weren’t actually taking it. learning not anymore.

However, it’s much more likely that more students passed because they studied harder and their schools did more to help them clear a bar that suddenly mattered; in other words, that grades increased because student performance improved.

So, with that aspect of the past as prologue, what will happen if Question 2 prevails and students no longer have to pass the 10th grade MCAS, which now also includes a science exam, to earn their high school diploma?

He Massachusetts Teachers Association, which has spent millions in its effort to eliminate the requirement that students pass the 10th grade MCAS to graduate, maintains that the tests will still be an effective tool for evaluating high school performance without so-called high stakes and that students They will learn nothing less.

That assessment may not reflect an accurate understanding of adolescent nature.

As the state Secretary of Education, Patrick Tutwiler, said. noted in a recent Harvard forum on Question 2, “High school students won’t take it seriously in the future, so it won’t be a useful assessment anymore.”

You are right. Based on history, we should expect MCAS results to decline, perhaps dramatically.

If that happens, does anyone think the MTA will argue in favor of reinstating the test as a graduation requirement so students will try more diligently? It seems more likely that the union will argue that since many students simply do not take the MCAS seriously, the exam results should not be considered an accurate measure of their mastery of the subject.

The situation that follows would cause the state’s efforts to improve education to regress toward the uneven efforts and significant and enduring pockets of mediocrity that prevailed before the state Landmark Education Reform Act of 1993. After all, as Secretary Tutwiler pointed out pointed out to the Harvard Crimson, “The only thing (question 2) does is deconstruct the current system. “He does not propose anything as a substitute.”

Attorney General Andrea Campbell underscored that same point in a recent letter to supporters explaining her opposition to Question 2.

“I have real concerns about Question 2 because not only would it eliminate our only statewide graduation standard, it would eliminate the standard and offer no replacement,” he wrote. “This would result in more than 300 different and unequal standards for high school graduation across the Commonwealth and potentially lead to haphazard assessments of students’ readiness for college and careers, and even wider inequalities in achievement.” and student opportunities.

Now, the MTA maintains that what really sparked the improvement in Massachusetts public education was not MCAS but the huge infusion of state dollars that came about thanks to the 1993 law.

However, that statement only tells half the story. Yes, the new state money was important, but so were the applicable rules. That’s how we know. The new dollars that came with education reform increased steadily, year after year, after the 1993 law went into effect. However, MCAS scores did not begin to increase significantly until 2001, when passing became part of earning a high school diploma.

As Gov. Maura Healey noted in an email to supporters urging them to vote no on Question 2: “In fact, as soon as we established MCAS as the graduation standard, we saw student performance take off across our state.” .

Without the MCAS graduation requirement, Healey added, “we will no longer hold all of our schools to the same high standards. Instead, it will go back to how it was before: with hundreds of different standards set by hundreds of cities and towns. “This will hurt our low-performing schools and poorest school districts the most.”

Healey and Campbell, Both liberal Democrats are absolutely right about this. As the state’s recent educational history demonstrates, “no” is the correct vote on Question 2.

The editorials represent the opinions of the Boston Globe editorial board. follow us @GlobeOpinion.