Statistical modeling, for the people it serves

Can family engagement close the achievement gap?

The one intervention that costs nothing may help the children who need it most. Here is what 25,391 students tell us.

High-income children earn mostly A's at nearly twice the rate of low-income children. This study asks whether family engagement narrows that gap, and finds it does: engagement protects low-income students 18% more than their higher-income peers.

25,391
students across two national survey waves
18%
stronger protective effect for low-income students
4
statistical models, all pointing the same way

The problem

A family's income still predicts a child's report card

Among the highest earners, 62.3% of children bring home mostly A's. Among the lowest earners, that figure is 36.5%. The 25.8 point gap between them is not a gap in ability. It is a gap in the resources a family can put behind a child, and those resources are not shared out evenly.

Most programs built to close it quietly widen it instead. Tutoring is claimed first by families who already have the time and the internet to find it. Advanced classes go to students whose parents know how to work the system. Even free summer programs run into transport, cost, and scheduling.

Family engagement looked different for one reason: it does not cost money. Showing up to a parent-teacher meeting, helping with homework, coming to a school event, none of it requires wealth. The real question was not whether engagement helps. It clearly does. The question was whether it helps more for the students furthest behind. Education researchers call this the compensatory hypothesis, and it is what this project set out to test.

Grouped bar chart of academic performance by household income. Among high-income students, 62% are high achievers and only 1% are at risk. Among low-income students, 37% are high achievers and 5% are at risk, with a much larger struggling group.
Figure 1. Academic performance by household income. The share of high achievers climbs steadily with income, while the at-risk and struggling groups shrink.

Does engagement help disadvantaged students more than advantaged ones?

The data and the method

Building a measure that isn't just noise

25,391 K-12 students, drawn from a national survey and modeled so a single missed meeting never masquerades as a finding.

The data comes from the NCES Parent and Family Involvement in Education survey, combining its 2016 and 2019 waves. After cleaning, 25,391 students remained, each with grades, an at-risk flag, and days absent, alongside eight school activities, homework habits, cultural enrichment, income, parent education, and family structure.

A single missed event says nothing on its own, it might just be a scheduling clash that week. So rather than model each activity separately, I built three composite measures to capture the breadth of a family's involvement instead of any one data point: a count of eight school activities, a standardized homework-involvement score, and a weighted cultural-enrichment score.

Testing the compensatory idea meant testing an interaction, not just a main effect. Entered separately, income and engagement can only tell you engagement helps on average. An income-by-engagement term is what lets the data say whether it helps unevenly, which is the entire policy question.

The one line that answers the question

step_interact(~ income : school_engagement) # A negative, significant coefficient here means engagement # lowers risk more for low-income students: # the compensatory signature we set out to find.
R 4.3tidymodelsggplot2nnetMASS75/25 split10-fold cross-validation

Who engages, and why

The gap in engagement is smaller than you'd think

Higher-income families do engage more, averaging 4.54 of the eight activities against 3.66 for lower-income families. But that 0.88 activity gap tracks structural barriers, inflexible work hours, transport, unwelcoming schools, far more than it tracks interest.

Where those barriers are lifted, low-income families show up at comparable rates. That matters, because it means the lever here is opportunity, not motivation.

Chart comparing average family engagement by income level: higher-income families attend about 4.5 activities on average, lower-income families about 3.7.
Figure 2. Average school activities attended, out of eight, by income.

The core finding

The same activity does more for the students who have less.

−0.20

The income-by-engagement coefficient is negative and significant (p = 0.009). In plain terms, each added activity lowers a low-income student's at-risk odds by roughly 18%, against 10% for a higher-income student. An effect this size would appear by chance less than 1% of the time.

What the numbers show

Engagement helps everyone, and helps them unequally

Move a student from low to high engagement and both groups improve. The students who start furthest behind gain the most, relative to where they began.

Line chart of the share of high achievers rising with engagement for every income group. Low-income students rise from about 32% to 44%, the steepest relative climb; high-income students rise from about 54% to 67%.
Figure 3. Share of high achievers by engagement level and income. Every line rises, but the lower-income lines climb most steeply relative to their starting point.

At low engagement, 32% of low-income students earn mostly A's. At high engagement, 44% do, a 37.5% relative jump. Higher-income students climb from 54% to 67% over the same range, a 24.1% relative gain. The wealthier group still gains more raw percentage points, but the lower-income group gains more relative to where it started. That is the compensatory effect, and it holds across every model that tests it.

Panel of interaction plots showing predicted outcomes across engagement levels for different income and parent-education groups, with steeper protective slopes for the lower-resource groups.
Figure 4. Modeled interaction effects. The protective slope of engagement is consistently steeper for lower-resource groups, the visual signature of the interaction term.

Not every form of engagement carries equal weight. Ranked by standardized effect on at-risk odds, homework involvement is the clear front-runner.

  1. 01

    Homework involvement

    Odds ratio 0.59, a 41% drop in at-risk odds per standard deviation. The single strongest predictor in the model.

  2. 02

    Cultural enrichment

    Library trips, reading, museums and shared activities carry a real, significant protective effect.

  3. 03

    Parent-teacher conferences

    Low cost, high frequency contact that almost every school already offers.

  4. 04

    Breadth of school engagement

    Odds ratio 0.90 per activity. Showing up across many activities matters more than any single event.

Coefficient plot of predictors of at-risk status. Homework involvement and engagement measures reduce risk, while having a disability is the largest single risk-increasing factor.
Figure 5. Standardized predictors of at-risk status. Note that having a disability is the strongest single risk factor here (odds ratio 1.61), and calls for its own targeted support rather than family engagement alone.

One question, tested four ways

Why four models instead of one

Grades, risk, and absences are three different kinds of outcome. Each needs its own model, and running several lets them check each other.

ModelPredictsWhy this oneCross-valTest
Multinomial
logistic
Four grade bands Handles unordered categories without assuming a rank. This is the primary model. 62.9%62.2% Stable
Binary
logistic
At-risk flag An early-warning screen, with interpretable odds ratios. 0.80 AUC0.21 AUC Overfit
Poisson
regression
Days absent Built for counts: non-negative, no upper ceiling. 4.55 RMSE4.37 RMSE Improved
Linear discriminant analysis Four grade bands Rests on different assumptions than logistic regression, so it acts as a convergence check. 62.6%62.1% Stable

The trap I documented

The binary model hit 94% accuracy by predicting almost everyone as not-at-risk, useless for the 6% it was meant to catch. Its cross-validated AUC of 0.80 collapsed to 0.21 on held-out data. Overall accuracy lies when classes are this imbalanced. The honest version of this project reports that failure and the fix, class weighting and threshold tuning, rather than the flattering number.

The robustness check

The multinomial model and the linear discriminant analysis rest on different statistical assumptions, yet land within half a point of each other, 62.9% against 62.6%. When two methods that disagree on the math still agree on the answer, the finding is unlikely to be an artifact of modeling choices.

Receiver operating characteristic curves for the multinomial model across grade categories, each bowing above the diagonal chance line.
Figure 6. ROC curves for the primary model, one per grade band.
Confusion matrix for the multinomial model, with the heaviest counts along the diagonal indicating correct classifications, strongest for the two middle grade bands.
Figure 7. Confusion matrix. Predictions concentrate on the diagonal, strongest for the two central grade bands.

What to do about it

Target the outreach, don't spread it thin

A program open to everyone in the same way is claimed first by the families with the most slack. The data argues for the opposite instinct: aim it at the students it helps most.

Where the evidence points

  • Homework-help sessions at school, coaching parents to support effort, not supply answers
  • Personal outreach to lower-income families, not a blanket invitation
  • Removing the real barriers: transport, childcare, evening scheduling
  • Parent-teacher conferences as the low-threshold entry point
  • Dedicated support for students with disabilities, the strongest risk factor here

Where good intentions fall short

  • Universal programs with no targeting, captured by the most flexible families
  • Fundraising galas as a primary engagement channel
  • One-size messaging that ignores families' actual barriers
  • Weekday daytime events that quietly exclude working parents
~$200
per student, per year, for a homework-help program
~$12,000
cost of a single grade retention, per student
18%
lower at-risk probability, at a fraction of the cost

What it taught me

The honest version of the story

I expected engagement to lift every student by about the same amount. Finding instead that it does more for the students starting furthest behind was the most hopeful result in the project: an equitable intervention does not have to be an expensive one.

The binary model's collapse was the sharper lesson. It is tempting to report the number that looks best. The version I stand behind shows the failure next to the fix, because a model that catches none of the students it exists to catch is not a success, whatever its accuracy score says.

The interaction is correlational, and I would want to strengthen the causal claim before a district spent real money on it: matching similar families who differ in engagement, natural experiments around policy changes, and tracking students over time to see whether the effect compounds across a school career.

Equity doesn't always need a bigger budget. Sometimes it needs better aim.

Four models, one steady signal: family engagement protects low-income students more than it protects anyone else. That is a lever most districts could pull tomorrow, and a reason for parents to believe their time at the kitchen table counts.