Every choice cycle, New Haven families rush to rank schools before the district's enrollment window closes. Some spend weeks researching and building their rank-order list; others add their top choice and call it a day. For every family, the stakes are high: a poorly built list can leave a student without a school they chose. Those unmatched families become flight risks, with charter, private, microschool and homeschool options all growing.

New Haven saw that risk and acted on it with research-grade interventions, detailed here. The district is an innovator among US choice systems, but other countries have worked on the frictions families face at enrollment for years. Chile runs a single centralized match for its entire K-12 system, shuttling millions of applications and students across the country in a single match. The question for a US district is no longer whether the warning works; New Haven answered that. It is whether it keeps working across cities, over time, and at scale. Chile has spent nearly a decade finding out. Four lessons from that decade stand out for US districts.

1. The Families Most at Risk Feel the Safest

Chile's survey of applicants turned up an uncomfortable pattern: the families in danger of going unmatched were often the ones who felt done. Applicants whose lists carried a real risk of no placement overestimated their chances of admission by 32 points on average, and more than a third of applicants stopped searching because they believed a school already on their list would take them. Most knew their first choice well, but less than 20% could recall details about nearby alternatives. The mistake also runs the other way. In Chile's college admissions system, about 40% of applicants left their true first choice off their list, some of them with a real chance of getting in, and the same biased beliefs about admission chances drive both errors.

For New Haven, that reframes the family who adds a top choice and calls it a day. That family isn't disengaged; it's confident. Confidence is what a warning has to correct.

2. A Warning Doesn't Need to Move Everyone

In Chile, about a fifth of warned at-risk applicants added schools to their lists, a response that stands out among research-tested interventions for actually getting families' attention. The families who acted gained a great deal. They cut their risk of going unmatched by more than half, got into their preferred choices at higher rates, and even went on to score higher on standardized tests years later.

A warning isn't meant to reach every family. It is meant to reach the families whose list is about to fail them, and to change what happens next. New Haven's results follow the same pattern, as the previous piece in this series describes.

3. Timing Is an Equity Decision

Most districts already explain how their choice process works. There is an FAQ page, a school fair, perhaps a virtual information night. Those are necessary, but they are not sufficient: they describe the rules to everyone at once, but none of them can tell a family that the list it is building is about to fail. Chile's experience points to something different: guidance that reaches families at key moments -  as they search, as they submit, and before the window closes - and that speaks to the list in front of them.

Timing matters most for the families with the least help. Feedback on a family's own list, delivered close to the deadline, is especially effective for low-income households, which tend to start with the least accurate picture of their chances and are the least likely to go looking for help on their own. In New Haven, where a majority of students are FRPL eligible, that is not a niche concern. It means the warning has to find families where they already are: inside the application, while there is still time to add a school.

4. Scale Holds When the Platform Does the Work

Many promising interventions fade as they grow beyond a pilot. A program that works when a small team runs it with care tends to lose quality once it depends on hundreds of staff, and its costs climb with every family it adds. Chile sidestepped that by building the warning into the application itself. Automating delivery through a central platform is what lets a policy like this grow without the usual drop in quality or rise in cost, and Chile's system went on to reach every city and every grade. The same approach has since carried into Chile's national college admissions match, where a nationwide version in 2023 roughly doubled the chances that initially unmatched students were admitted.

For a US district, the lesson is practical: the warning does not have to be staffed into existence. A district the size of New Haven does not need a counselor for every family at risk. It needs a warning that runs on its own, every cycle, for every family who applies.

Better information changes more than individual lists. When families across a system act on it, some will reach for the same high-quality schools, and seats there can run short, especially in disadvantaged neighborhoods. That is worth planning for, but it is not the whole picture. Families tend to know their first choice well and little else nearby. Recommendations tailored to each family, rather than one ranking of the "best" schools for everyone, spread applications across more schools, and they put good schools that families had never considered back on the map. Over time, that transparency changes what drives demand. When families can see and compare their options, demand follows quality rather than word-of-mouth popularity, giving every school a reason to compete on what families truly value.

A district that matches families on ranked lists does not have to rediscover any of this on its own. Chile has already worked through where families' confidence misleads them, which families a warning needs to reach, when it has to arrive, and how to run it across an entire country. TetherEducation is embedded in that work: from the national admissions system redesign to after-market waitlist administration to federal policy advising. Tools built from that published field research change a district's starting question: it is no longer whether the approach works, but how it fits the district's own window, its families and its schools. TetherEducation's platforms are built on a decade of that research, and New Haven has already shown what the approach looks like inside a US district.