If your family is heading into private school admissions season, you’ve probably already discovered that test prep is its own industry. Tutors, group courses, workbooks, online platforms, practice test bundles — the options multiply fast, and most of them promise the same thing: higher scores.

The instinct is to do more. Sign up for the course and the tutor. Buy every workbook. Stack interventions. But here’s the thing: more spending doesn’t reliably produce better scores. Smarter spending does.

As someone who thinks about this problem every day — I build tools that help kids practice math for the SSAT and ISEE — I’ve seen what actually moves the needle and what just feels productive. The difference matters, especially when you’re investing real time and money into your child’s preparation.

What the evidence says about score improvement

The research on effective test preparation is surprisingly consistent. A few principles come up again and again:

Targeted practice on weak areas beats broad review. A student who’s solid in geometry but shaky on ratios will improve more from fifty focused ratio problems than from a hundred mixed-topic questions. Diagnosis before treatment — know what’s weak before deciding where to spend time.

Volume of practice matters more than hours with a guide. Pattern recognition comes from repetition. Students who work through a high volume of questions — and actively engage with each one — build fluency faster than students who passively listen to someone explain concepts.

Immediate feedback accelerates learning. There’s a big difference between checking an answer key at the end of a problem set and getting a step-by-step explanation the moment you get something wrong. The closer the feedback is to the mistake, the more the correction sticks.

Consistency over weeks beats cramming. Spaced practice — shorter sessions spread over a longer period — is one of the most well-documented findings in learning science. A student who practices thirty minutes a day for eight weeks will outperform one who crams for a full weekend before the test.

Think of it as the 80/20 of test prep. A small number of strategies drive the majority of score gains.

Where families typically spend — and where it actually pays off

Here’s how most families allocate their test prep budget, and an honest look at the return on each:

Private tutoring is the biggest line item for most families, and it has the highest variance. A great tutor — one who diagnoses a student’s specific gaps, adapts their approach in real time, and teaches problem-solving strategies — is genuinely worth it. The problem is that great tutors are hard to find. Many tutors, even well-credentialed ones, end up simply working through problem sets alongside the student. That’s supervised homework, and it doesn’t justify premium per-hour rates. Before committing to ongoing tutoring, ask: is this tutor doing something my child couldn’t do with the right self-study tools? If the answer is “not really,” that money might work harder elsewhere.

Group courses provide structure and accountability, which matters for some students. But the one-size-fits-all pacing is a real limitation — advanced students get bored covering material they’ve already mastered, while struggling students can’t slow down when they need to. You’re paying for a schedule, not for personalization.

Workbooks are inexpensive, which is their main appeal. But they have no feedback loop. Students tend to practice what they already know (because it feels good) and skip what’s hard (because it doesn’t). Without adaptivity, a workbook can’t tell your child why they got a problem wrong or steer them toward the topics that need the most work.

Practice tests are essential — they build test-day stamina, reveal weak areas, and familiarize students with timing pressure. But there’s a limited supply of official ones, so they’re best used strategically: one at the start to diagnose, a few during prep to track progress, and one near the end to simulate the real experience.

The pattern I see again and again: families over-invest in tutoring hours and under-invest in targeted, high-volume practice with immediate feedback. The first feels more “serious.” The second actually drives results.

A framework for high-ROI test prep

If I were advising a friend on how to structure their child’s SSAT or ISEE preparation, here’s what I’d suggest:

1. Diagnose before you spend. Have your child take a practice test and break down the results by category — not just “math” but algebra vs. geometry vs. data analysis. You can’t optimize what you haven’t measured.
2. Prioritize targeted practice. Once you know the weak areas, direct the majority of prep time there. Broad review is comforting but inefficient.
3. Choose tools with built-in explanations. An answer key tells you what’s right. A good tool tells you why — and that’s where learning happens. Look for practice resources that provide step-by-step solutions, not just final answers.
4. Reserve tutoring for true blockers. If your child genuinely can’t grasp a concept through practice alone — say, a foundational gap in fractions that’s blocking everything downstream — that’s when a tutor earns their fee. Use them surgically, not as the default. You can essentially be the tutor too!
5. Track progress and adapt. Weak areas shift as your child improves. What needed attention in week two might be solid by week six. Review the data regularly and reallocate focus accordingly.

This is the approach we built Growbi around — AI-generated practice questions targeted to specific math topics, instant feedback with step-by-step explanations, and progress tracking so you know when to shift focus. It’s not the only way to do this, but it’s designed to make the high-ROI strategies accessible without needing to coordinate multiple expensive resources.

Allocate where it counts

The families who get the best results aren’t necessarily the ones who spend the most. They’re the ones who diagnose first, practice with purpose, seek feedback, and adjust along the way. That’s a more boring story than “we found an amazing tutor who transformed everything” — but it’s a more reliable one.

If you want to try the approach, Growbi is free to start — no commitment, just practice.