The summer of the AI tutor

A $4/month digital tutor can teach any student who will sit still for it.

Summer break is starting across much of the United States, and parents shopping for ways to keep their children learning will find a market of AI tutoring tools that barely existed three years ago. Khanmigo costs $4 per month, Photomath about $10, and ChatGPT nothing at all. These tools differ on a foundational question: whether an AI tutor should help a student understand a problem or solve it for them.

Four dollars a month

In 1984, educational psychologist Benjamin Bloom reported that students who received one-on-one tutoring performed two standard deviations above their classroom-taught peers, meaning that the average tutored student outperformed 98% of students in conventional settings. Bloom called the finding the “Two Sigma Problem” because society could not afford to give every child a personal tutor. When Khan Academy launched Khanmigo in 2023, Sal Khan cited Bloom directly, describing the tool as an attempt to give every student “what wealthy families have always been able to buy.”

Subsequent meta-analyses tempered the original claim. Effect sizes landed closer to 0.5 to 0.8 standard deviations, and the original study had held tutored students to a 90% mastery threshold while classroom students needed only 80%. The tutoring effect was real, and large by the standards of educational interventions, but closer to one sigma than two.

The cost barrier remained regardless. Human tutoring runs $25 to $80 per hour in the United States in 2026. A full year of Khanmigo costs $44, and parents can add up to ten children to a single subscription. A year of AI tutoring for an entire family costs less than one hour with most human tutors. The economics that prevented Bloom’s finding from scaling have collapsed.

Teaching vs. cheating

The tools that emerged from this collapse split along a design-philosophy line. Khanmigo uses the Socratic method: when a student types “I don’t understand fractions,” it asks “What do you already know about dividing things into equal parts?” Photomath takes a different approach. Point a phone camera at a math problem and the app returns an instant step-by-step solution. ChatGPT, which was never designed as a tutor, will complete any assignment on request.

Ninety-two percent of students now use AI tools when studying, and a majority describe their usage as learning-oriented. Their tool choices tell a different story. Students accustomed to instant solutions find Khanmigo’s Socratic approach frustrating. It asks questions when they want answers and refuses to accelerate past confusion. The friction that makes Khanmigo less popular is the same friction that produces deeper comprehension.

The metrics of learning

Khan Academy has published the number that quantifies this dynamic: only 15% of students with access to Khanmigo engage with it regularly, despite 108 million total interactions since the tool’s 2023 launch. The organization averages 269,000 Khanmigo interactions on school days, a figure that sounds large until measured against the millions of students who have access. Kristen DiCerbo, Khan Academy’s Chief Learning Officer, acknowledged that early usage “has varied” and that “some chats help students move forward more than others.” A redesigned experience will roll out to all district partners this summer, aimed at closing the gap between access and adoption.

The redesign may matter less than a quieter shift in how Khan Academy measures success. The organization now tracks “next-item correctness”: whether a student can solve the next problem independently after receiving AI help. This metric separates two phenomena that both resemble learning: solving a problem with AI assistance, and solving the next problem without it. Every AI tutoring tool on the market can improve a student’s performance while the AI is helping. Improving performance after the AI stops helping requires a tool that teaches.

A delicate problem

Bloom framed the Two Sigma Problem as a question of supply: too few tutors for too many students. AI has answered that question at a price point Bloom could not have imagined. A $4 subscription can provide unlimited, patient, Socratic questioning to any child with an internet connection, in any subject, at any hour. The supply problem has given way to a demand problem. Students must choose to engage with a tool that makes them think when a tool that provides answers sits in the next browser tab, and the early evidence suggests that most of them choose the answers. Khan Academy’s summer redesign and its next-item-correctness metric represent a bet that design can close this gap. The coming school year will test whether it can.