I am approaching the 30th anniversary of my Dec. 7, 1982, encounter with East Los Angeles math teacher Jaime Escalante. That day changed my life. If I had not met the guy who was helping so many Hispanic kids master calculus, I wouldn’t be writing columns today. I also wouldn’t be having frequent arguments about how much low-income students can learn.

Escalante proved that the children of day laborers can do well in challenging Advanced Placement courses if given enough time and encouragement to learn. In 1987, he and his Garfield High School colleague Ben Jimenez were responsible for 26 percent of all Mexican American students in the country who passed AP calculus exams.

Several of these students were not doing well in other subjects. And many people, including some educators, still believe that AP can’t help you if you are not already a good student. That is why many schools still bar average students from taking AP.

Some readers regularly attack my reports on research suggesting that AP courses help the lowest-performing students prepare for college and that they benefit even if they fail the AP exam. So let me aggravate them again by offering a just-released report by the Mass Math + Science Initiative that reveals what AP has done for more than 8,000 students in their program.

The MMSI, created by the nonprofit Mass Insight Education, is designed to increase student participation and performance in AP math, science and English courses. In 2010, more than 7,800 AP exams were taken in MMSI schools with an eligible student population of 18,955. Only 3,685 AP exams were taken in a comparison group of schools that had 22,911 eligible students.

College matriculation rates for low-income students in MMSI schools were 14 percent higher than state and national averages. The rates for African American students in the program were nearly 20 percent higher than state and national averages.

Getting into college, however, has proved to be weak indicator. Plenty of campuses take anyone who applies. Perhaps a better test of a high school program’s value is, out of those who enroll, what percentage survive the first year and show up for a second year. Scholars call this the persistence rate. Students coming out of MMSI schools have a 77 percent persistence rate in two-year colleges and a 90 percent rate in four-year colleges. This is substantially above the two-year college persistence rate of 54 percent for Massachusetts students not in MMSI, and the four-year college persistence rate of 79 percent.

The most powerful argument in the new report comes from an examination of students in the MMSI program who took AP courses but did poorly on the grueling three-hour exams. The highest score on an AP exam is 5; the lowest is 1. Some critics have said high schools should not allow students to take AP courses if they are likely to get that bottom grade. The MMSI study suggests they are wrong. I welcome their cranky reactions on my blog.

The college attendance rate for MMSI students who got a 1 on an AP exam was 77 percent, much higher than the 53 percent college attendance rate of MMSI students who did not take AP exams. MMSI students with scores of 1 who go to two-year colleges have a persistence rate of 70 percent, more than those who don’t take an AP exam. But the news is even better for another group of low-scorers. MMSI students who got just a 1 and attended four-year colleges have a persistence rate of 92 percent, compared to 92 percent for those who score a 3, 94 percent who score a 4, and 99 percent of those who score 5.

That was one of the lessons Escalante taught me. He railed against teachers who dropped low-performing students from AP courses and did not let them take the final exam. Even struggling students, he said, are learning things that will give them an advantage in the next stage of their lives.