Peter Timothy Anderson is the head of school at Washington Latin.

Picture this: Three students stand near the fence to see a game being played on the other side. One student is tall and easily sees over the fence. The second is shorter and barely peeks over the pickets. The third is the shortest and finds himself staring at the wood, not the game. These students all have the same opportunity to peer over the fence, but circumstances beyond their control affect their ability to see the game. This is a case of offering equal access.

Now imagine that the shortest student is provided a step ladder, the second-tallest stands on a milk crate, and the tallest remains standing on his own two feet. All three students can see the game thanks to these accommodations, and their experiences are equitable.

This distinction between providing equality of access and ensuring equity in the experience is crucial in education. It is arguably the central tenet of our public school system: All students in the United States deserve a free quality public education, regardless of their financial status, learning challenges or other needs that can — in the language of the analogy above — keep them from seeing over the fence.

The District, with its robust charter school sector and a rich array of D.C. Public Schools choices, is positioned to provide not just equal access but also equality of opportunity in our public schools. Choice is essential, as it allows families to select the right place for their children. More than 70 percent of D.C. public school students are attending a school selected through the MySchoolDC common application and lottery system rather than their assigned school. This is powerful: Students in our city are not bound by geography to a certain school model or level of school quality.

School quality is on the rise in the District. The recent D.C. Policy Center report on the State of D.C. Schools makes plain that our traditional public and public charter schools alike have outpaced other cities across the country in improving academic performance.

While this progress is good news, it masks underlying inequities. This same report shows that students considered at-risk for academic failure — those who are homeless, recipients of welfare or food stamps or who are more than a year delayed in high school — are not improving at the same rate as their more advantaged peers and are falling further behind. With nearly half of D.C.’s public school population defined as at-risk, every D.C. resident has an interest in addressing this problem.

One obvious answer to this troubling gap is simple: ensure our at-risk families have access to the very best schools. As the head of school at Washington Latin, a public charter school in Ward 4, I have seen how vulnerable students can benefit in an environment with the resources and approach to serve them successfully. In the case of our school, students from all backgrounds benefit from our small classes, especially students who are struggling or need extra support.

Our classical curriculum and highly relational approach engage students who might otherwise “fall through the cracks.” We know that it works, demonstrated by the academic achievement of our students with disabilities. And, last year, 58 percent of Latin’s at-risk students who took the high school PARCC exam were proficient in English, more than twice the city average.

This solution of sending more at-risk students to the best school is more difficult to accomplish than it might seem. As more families are choosing to raise their children in the District, there is an ever-increasing demand for top-ranked public schools. But we all know that when there is not enough of anything to go around (in this case, quality schools), our most vulnerable students are likely to be the first to be squeezed out.

Having made significant progress in decoupling students’ geography from their educational fate, the District must ensure that our most vulnerable students can access the best schools in the District and are not left behind as the city goes through a positive revitalization. We must act now to create mechanisms that ensure equity rather than simply providing equal access.

We are lucky to have a powerful lever in this work: the common lottery, MySchoolDC. Given that most public school families use it to select and apply to the right school for their children, the lottery is a tool for ensuring equity. Schools recruit enthusiastically for more at-risk students — and we have families from all eight wards who rank us at the top of their lottery choices. However, the system does not allow us to adjust our applicant pool to provide a preference for at-risk students.

Two potential amendments to the D.C. Code point the way forward. One amendment would allow public charter schools to provide a preference or set-aside for at-risk students, giving us the opportunity to bring our resources to bear in communities where we can be most helpful. Another would require a review of the statutory definition of at-risk to ensure that we are identifying and including the students in most need of support. Both of these considerations would serve District families and allow public schools to help achieve the city’s overarching goal of continually improving the academic performance of all its students.

At Washington Latin, we have long stood with other D.C. public charter school leaders in calling for the kinds of changes that will have the greatest impact on the most vulnerable students. As educators, we care deeply about the ability of all children to succeed and thrive. We believe that all students, from every background, deserve a quality education that develops knowledge, understanding and humanity. And we are committed to engaging with young people across the city to play a part in their learning and growth.

We are proud of the ongoing progress the D.C. public school system is making and equally proud of contributing to that. The State of D.C. Schools report makes clear that there is so much more to be done. Better enabling public charter schools to continue to do our part — to stand up for our children and to invest in our community — will be a positive next step toward the goal.