Derivita & The 2 Sigma Problem
Bloom named the problem. Here's what solving it looks like for your district.
In 1984, Benjamin Bloom proved one-on-one tutoring produces the largest learning gains ever documented. He called finding a scalable version of that the defining challenge of modern education. Derivita was built to answer it.
Bloom proved what's possible. The question was always scale.
Benjamin Bloom ran a controlled experiment with identical students, identical materials, and identical time. The only variable was the learning condition. One group sat in a conventional classroom of 30. Another worked one-on-one with a tutor.
The tutored group outperformed 98% of conventionally taught students. Two full standard deviations above the mean. Bloom called it the 2 Sigma Problem — not because 2 sigma is the limit, but because we already know it's possible. The problem is we can't afford to do it for everyone.
His follow-on question — the one that has driven education research for 40 years — was: can group instruction ever approximate what a great tutor does?
Bloom's Three Conditions
Same students. Same time. Same materials. The tutored group's average student outperformed 98% of the conventionally taught group.
He didn't just name the problem. He mapped the solution.
Bloom identified the alterable variables that most move student achievement — ranked by effect size. Most educational technology addresses the low-impact variables. Derivita was designed to address the high-impact ones. The variables marked below are what Derivita directly operationalizes.
| Variable | Effect Size | How Derivita Addresses It |
|---|---|---|
| Feedback-corrective |
|
Core CAS function — context-specific formative feedback on every student response |
| Cues and explanations |
|
Dynamic worked-out solutions that motivate each step and connect prerequisite concepts |
| Student time on task |
|
LMS-native integration drives daily use — 85%+ license utilization vs. ~10% industry average |
| Student classroom participation |
|
SpotCheck drives whole-class discourse and Building Thinking Classrooms workflows |
| Homework (graded) |
|
Auto-graded open-ended homework with instant results, not just right/wrong |
| Cooperative learning |
|
SpotCheck enables whole-class mathematical discourse, including anonymous participation that reduces the friction of low confidence, so every student can engage in the conversation. Beyond the classroom, PLC common assessments with automated data aggregation give instructional teams a shared data set to work from, extending cooperative practice to the professional level and turning teacher collaboration into a genuine collective practice rather than a comparison of individual impressions. |
| Higher order questions |
|
CAS enables open-ended questions competitors can't ask — or grade |
| New science & math curricula |
|
Derivita supports any curriculum. Switching alone moves the needle far less than changing teaching practice. |
■ Variables Derivita directly addresses · Source: Bloom, B.S. (1984), adapted from Walberg (1984).
"Derivita is drenched in good pedagogy. Absolutely drenched. We just disguise it as a math quiz."
Technology didn't make Bloom's list in 1984. Not because technology doesn't matter, but because technology that doesn't change teacher practice doesn't move the needle. Derivita was designed around the variables that do.
How Derivita's feedback loop is what Bloom was describing.
A great tutor doesn't hand you the answer when you're wrong. They recognize what you were trying to do, name the specific error, and send you back into the problem. That feedback is corrective, immediate, and tied to your actual thinking, not a generic hint. This is Bloom's highest-impact variable: feedback-corrective instruction, effect size 1.00. Derivita delivers it at scale, automatically, on every single response.
The three outcomes correspond to Bloom's feedback-corrective mechanism — the highest-impact alterable variable (1.00σ) short of one-on-one tutoring.
Every design decision traces back to the same research.
What would this mean
for your district?
The ESSA Level III study found that good teaching practices enabled by Derivita — PLCs, formative homework, common assessments — naturally result in one additional question per day. That's not a prescription. It's what happens when teachers engage with the platform. Enter your district size to see what the research suggests.
The ESSA study found teachers using PLCs, formative homework, and common assessments naturally averaged 1 additional question/day — without being told to.
↓ Your Projected Impact
Progress toward Bloom's 2 Sigma ceiling
* Based on 2026 ESSA Level III study findings (+0.33–0.45 SD per additional question/day). Individual district results vary. Gains are associated with good teaching practices enabled by Derivita — not from software alone.
Independent research you can trust.
We didn't tell teachers to assign one more question a day, or train them on a new teaching model. The additional questions were a natural byproduct of educators blending Derivita into their own teaching practices; working with individual students, leading whole-class instruction, collaborating in PLCs, or building common assessments at the school and district level. Then a third-party research firm measured what happened.
The study covered 1,647 students across 17 secondary math teachers, with strong statistical controls for prior achievement and teacher effects.
IV
III
The largest published effect size for point intervention products is 0.14. Derivita's is 0.34–0.45 — as a supplemental tool with no prescribed implementation model.
Read the Full StudyBloom named the problem.
Let's solve it for your district.
Derivita brings mastery-based learning into the classroom at scale, inside the LMS your teachers already use, without adding to their workload.
Supplemental math · Grades 6–Calculus III · ESSA Level III & IV evidence · 26 states