In 2007, while writing about military recruiting at high schools, I met a fresh-faced JROTC cadet who planned to enlist after graduation. His older brother was already serving in Afghanistan as part of the U.S. response to the terrorist attacks on September 11. The student, who was a seventh-grader when the hijacked airplanes struck, eventually joined the Army and followed his brother to war.

Now we are at the 15-year anniversary of the 9/11 attacks, and the connective tissue is even fainter for many students. The vast majority of today’s K-12 students weren’t even born when events unfolded on 9/11. So how do teachers make this relevant to young learners? And how much of what they say is mandated by state standards?

On the question of state standards, the short answer appears to be “not much.” That doesn’t mean 9/11 isn’t being taught. However, much of how these lessons unfold is left up to the discretion of individual teachers, said Jeremy Stoddard, an associate professor at the College of William & Mary who has been tracking 9/11’s curricular footprint almost from the beginning.

One of his first projects: how textbooks published immediately after 9/11 addressed the topic compared with how Pearl Harbor was described. Time was an obvious factor, he says. Because of the chronological distance from the Japanese attack on the Hawaiian Harbor on December 7, 1941, “it was written much more factually—this is what happened on that day,” Stoddard said. By comparison, the tone of the September 11 content “was more emotional and nationalistic,” he says. In subsequent textbook editions, certain discredited elements of the 9/11 narrative had even been dropped—namely, that the U.S. went to war to prevent its enemies from utilizing weapons of mass destruction.

In 2011, Stoddard and Diana Hess (now the dean of the University of Wisconsin School of Education) found most states didn’t require 9/11 to be taught as a stand-alone topic. That hasn’t changed much in the ensuing half-decade, Stoddard says. There will always be variations in instruction, even with a more strict mandate for curriculum, Stoddard says.

Those instructional decisions are best when based on “who their students are, what the teachers’ goals are, what they know about how their class fits into the broader curriculum,” Stoddard says. “Those are all things that we want professional teachers to do.”

Here’s one example of that kind of personalized instruction: Jana Joy, a U.S. history teacher at Eula High School near Abilene, Texas, told USA Today she has each of her students choose one victim of September 11 and use that person’s biographical information as a lens:

Using newspaper reports from the aftermath, the students dive deep into the lives of victims in an effort to humanize the events. “It really affects the kids in different ways,” Joy said. “They pick their person off the website and really get to know that person. They find out what they were doing, where they were for the attacks. It puts everything into perspective.”

In Colorado—as in many states—there is no mandate on how 9/11 must be taught, and local districts, schools, and teachers can opt to craft their own approach. That can mean being prepared to navigate some difficult waters—and answer tough questions—as students process their own responses to the often difficult and emotional content. Jake Cousins, an eighth-grade teacher at STRIVE Prep-Sunnyside, a northwest Denver charter school, told Colorado Public Radio about his approach:

“September 11 was really about how do people process loss and how does a traumatic event on a national or global level translate to an individual or to a community? … We spun it into conversations we were having about everything from Medieval Europe, to the Arab Spring and subsequent conflicts that kind of have been a part of our national understanding since then. I think giving students the chance to grapple with these themes is powerful.”

Over 40 states have implemented the Common Core State Standards for English language arts and mathematics, which put greater emphasis on developing students’ critical-thinking skills and applying them to a broad range of academic area. That’s brought a shift in the approach to other core subjects. Some states and large districts have drawn on drawing on the College, Career, and Civic Life framework—known as the “C3”—from the National Council for the Social Studies to inform their state standards. In harmony with the Common Core, it emphasizes “using evidence and reasoning to draw conclusions about probable causes and effects, recognizing that these are multiple and complex.”

As a result, some states’ updated standards—like Illinois’, for example—dropped prior references to September 11 “not because it is seen as diminished or less relevant” but because almost all topics, events, and names were removed, says Stoddard. The underlying goal is for students to understand how the ripples from 9/11 still resonate and have influenced things like airport security as well as specific populations both in the U.S. and abroad, he added.

Indeed, as Lauren Camera reported for U.S. News & World Report, 9/11 has become an opportunity to teach students to challenge conventional wisdom and confront controversy, as illustrated by this lesson plan crafted by the American Federation of Teachers:

As students get older, sample lessons become more complex and include videos about events leading up to the attacks, how the day unfolded, as well as the cultural and racial implications the event had on certain populations, including Muslims and Sikhs. An exercise for students in grades 11 and 12, for example, asks students to debate statements like, “I’m willing to give up some personal freedoms, such as search of my bag, phone or phone records, if it helps national security,” and “After an attack like 9/11, it’s natural and unavoidable for there to be a cultural backlash against the race/culture/religion of the perpetrators.”

New York’s state standards also set high goals for students to be critical thinkers, incorporating elements of the recommended C3 approach, and even specifically confronting some of the misinformation about WMDs that fueled early support for the U.S. military response, and controversies over privacy rights:

Students will examine the decision to invade Iraq, which was based on allegations concerning weapons of mass destruction, and trace the course of the war. … Students will evaluate the USA PATRIOT Act, including constitutional issues raised about the violation of civil liberties by the Federal Government’s electronic surveillance programs.

And California’s state standards expect older students to put 9/11 into historical perspective and understand the geopolitical shifts that led up to the attacks:

When the Cold War ended with the fall of the Berlin Wall in 1989 and the breakdown of the Soviet Union in 1991, what kind of world did it bequeath? Why did the vision of a “New World Order” that U.S. President George H.W. Bush articulated in 1990—a vision of a world more stable, pacific, and predictable than the world of the past—fail to come to pass? Did 9/11 change everything? Or was the world in the 1990s less stable than it might have appeared at the time?

This is difficult work for both educators and students. But as sixth-grade teacher Lauren Hinojos told Colorado Public Radio, it’s also an opportunity to demonstrate that history isn’t static:

“I’ve had one of my kids even say to me, ‘Remember, it’s never going to be as real to us as it was to you. But we still want to know what’s going on and we still want to know as much as we can.’ I think by telling our personal stories, talking to their parents, hearing as many stories as they can, I think that helps make it real for students.”

This article appears courtesy of the Education Writers Association.