A full course, not a chat window
Give it your syllabus. Get your whole semester, taught.
ClassDay turns your syllabus into scheduled classes and teaches them one at a time.
Example class · illustration
Calculus II · Class 7: Absolute and conditional convergence
- 01Intro
- 02Core concept
- 03Examples
- 04Practice
- 05Summary
A series can converge without converging absolutely. If ∑aₙ converges but ∑|aₙ| diverges, the series is conditionally convergent, and rearranging its terms can change what it sums to.
Understanding check
Does ∑ (−1)ⁿ/√n converge? Say whether it converges absolutely, conditionally, or not at all, and why.
“It converges, the terms go to zero.”
Right conclusion, wrong reason. Terms going to zero is necessary but not sufficient: the harmonic series does that and still diverges. This one converges by the alternating series test, but only conditionally: ∑1/√n is a p-series with p = ½ ≤ 1, so it diverges.
From material to a running course.
It reads your syllabus
Topics, readings, deadlines, exam dates and term length are pulled out and structured.
It maps your semester
Your material becomes numbered classes on real dates, paced across the weeks you have.
It teaches each class
It sets your level from your answers, teaches one concept at a time, and re-teaches on request.
No syllabus? Name the subject and it builds the curriculum itself.
Every class is taught, then marked.
Provenance
Every claim is labeled: your material or broader context.
You always know where an explanation came from. Your own readings are marked apart from general knowledge.
Article 231 makes Germany accept responsibility for the loss and damage caused by the war.
The phrase “war guilt clause” appears nowhere in the treaty. It was a later German coinage.
This week
12 weeks · 24 classes · midterm week 6
Semester map
Week one to finals, laid out before you start.
Every class is numbered and dated, with deadlines and exams marked in place. The pacing keeps the material cumulative.
Graded, honestly
You get marked like it counts.
Written answers are graded against a rubric. You get what you had right, the main thing you missed, and one next step.
Your answer
“The seller bears the tax, because the law says the seller pays it.”
Main gap: who writes the check does not decide who bears the cost. The burden falls on whichever side of the market is less elastic.
Why structure
AI helps most when it teaches rather than simply answers.
A randomized controlled study tested an AI tutor built around active learning, scaffolding and targeted feedback. It produced larger learning gains than an in-class active-learning session on the same material.
2×
median learning-gain advantage over in-class active learning, same lesson content
83%
of students rated the AI tutor's explanations as good as or better than their instructor's
Both figures are results from Kestin et al., 2025, an independent study of a different AI tutoring system in introductory physics. They are not ClassDay results, and ClassDay has not been academically validated to produce them.
Harvard intro physics, N=194, crossover RCT. Median time on task: 49 min (AI) vs. 60 min (class). Students reported significantly higher engagement and motivation.
What are you taking this semester?
Your first course takes about five minutes to set up.