ADAPTIVE QUIZZES
Questions that re-tune.
Difficulty moves with every answer, and each result writes mastery back to your graph.
Sapling
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* AVAILABLE EXCLUSIVELY TO BOSTON UNIVERSITY STUDENTS
Upload a syllabus. Sapling reads your whole course, maps what you already know, and drills only what is slipping. It works from your own coursework, not the open web, and the AI never hands over the answer.
01
Ingest
Your syllabus, slides and lecture notes in. A model that knows your course out.
02
Map
Every concept linked to the ones it rests on, in your professor's own order.
03
Recall
Questions drawn from your material, returning right before you would forget.
SCROLL TO CONTINUE
Built by students who were tired of studying blind. Every answer cites the slide it came from, so you can check the source yourself. Free through beta.
A hundred names you don’t know yet.
Every concept in your course becomes a node. Right now, they're strangers.
The graph
You study. They connect.
Every quiz, note, and card you touch draws an edge. Structure appears.
The graph
Mastery is the color.
MASTERED
LEARNING
STRUGGLING
UNEXPLORED
See what you know.
Your whole semester, one living map, updated as you learn.
DRAG TO ORBIT · CLICK TO EXPLOREIngest
Drop in the whole course.
Ask ChatGPT for practice and you get generic exercises off the internet, then an empty box again. It forgets. Sapling works only from your class’s material: your professor’s slides, the syllabus, lecture notes.
And every student who adds their documents makes the AI understand the course better. One person’s lecture notes fill a gap in another’s slides, so the model learns what this professor actually emphasizes, how they word questions, which concepts they keep returning to. The more your class contributes, the sharper the context gets for everyone in it.
CS 112 · SYLLABUS.PDF
Wk 1 · Binary search trees: insert, searchWk 2 · Big-O notation: growth ratesMidterm · Oct 14: in class, Ch. 1 to 6Wk 4 · Recursion: base cases, stack depthWk 5 · Hash maps: collisions, load factorWk 6 · Graph traversal: BFS, DFSPS 3 · due Fri 11:59pm, GradescopeWk 8 · Dynamic programming: memo tablesWk 9 · Heaps and priority queuesWk 10 · Memoization vs tabulationFinal · Dec 9: cumulative, 3 hrsWk 12 · Dijkstra's algorithm: shortest paths
OCR · 4 PAGES12 CONCEPTS FOUND
GRAPH
+0
MASTERY 0% · UNEXPLORED
FLASHCARDS
+0
FRONT · AUTO-GENERATEDWhat does Big-O actually bound?
FORGOTHARDEASY
CALENDAR
+0
OCT 14Midterm · in class
OCT 18PS 3 · Gradescope
DEC 09Final · cumulative
SYNCED TO GOOGLE CALENDARQUIZ BANK
+0
Worst-case lookup in a hash map with chaining?
A.O(1)B.O(n)
DIFFICULTY ADAPTS TO YOUR ANSWERSAI tutor
Three ways to learn this. Your pick.
SOCRATIC
Never hands you the answer. It asks the question that gets you there yourself.
EXPOSITORY
Explains it straight: structured, sourced from your materials, at your level.
TEACHBACK
Flips the desk. You explain, and Sapling names exactly where it breaks down.
SOCRATIC MODE?
Before rotations: what does the “B” in BST guarantee about a node’s children?
left subtree smaller, right subtree bigger?
Right. So what breaks if one side grows far taller?
lookup stops being logarithmic
HINT LADDER2 / 4
It escalates only when you stall.EXPOSITORY MODE
AVL rotations, plainly.
Every node’s balance factor stays in {−1, 0, +1}. When an insert breaks that, one of four rotations restores it in O(1).
LEFT-HEAVY
→AFTER LL ROTATE
FOUR CASESLLLRRLRR
RETRIEVED FROM YOUR LIBRARY
lecture-07.pdfp. 12notes-wk4.md
TEACHBACK MODE
RECORDING · 0:42
“…so you rotate left when the right side gets too heavy, and, um, the parent just moves downand it’s balanced again…”
WHAT YOUR EXPLANATION COVERED
Rotation directionCORRECT
Which node becomes rootMISSING
Subtree reattachmentVAGUE
GAP FOUND
The right child becomes the new root, not the parent.
MASTERY 24% → 19%RE-EXPLAIN ↻
And much more
The rest of the grove.
Eight tools covering the whole arc of a course: quizzes and flashcards that test recall, notes and study guides that turn your materials into something usable, a tutor that talks you through what you missed, and a gradebook and calendar that keep the semester honest. Each one writes back to the same graph.
Card 7 of 12MA 242 · EIGENVALUES
FRONTWhat equation gives the eigenvalues of A?
BACKdet(A − λI) = 0, the λ that makes A − λI collapse.
Forgot 110 minHard 21 dayEasy 34 days
SPACED REPETITION
Knows what to review, and when.
Forgot, Hard, Easy: ten minutes, a day, four days. Sapling schedules; you show up.
Lecture 7 · EigenvaluesSAVED
λ scales v, it never turns it.
Solve det(A − λI) = 0 for λ,
then null(A − λI) for the
eigenspace.
CONCEPTS EXTRACTEDEigenvaluesDeterminantNull space
SUMMARIZEEXTRACT CONCEPTSGENERATE QUIZ
NOTETAKER
Notes that think.
Write normally. Sapling summarizes, pulls the concepts, and links them to your graph.
MA 242→MIDTERM 2 · OCT 24
Eigenvalues & eigenvectorsYou missed 4 of 6 here
DeterminantsShaky on 3×3 expansion
Vector spacesSolid, light review
Built from 11 library docsREGENERATE
STUDY GUIDES
Built from your gaps.
Pick a course and an exam. The guide is assembled from your own library, weighted to weak concepts.
QUESTION 4 OF 8MEDIUMHARD
EigenvaluesMA 242
If A v = λ v, what does λ tell you about what A does to v?
A.The angle A rotates v throughB.The factor A scales v by
3 right in a row on this conceptNEXT ↑ HARDER
ADAPTIVE QUIZZES
Questions that re-tune.
Difficulty moves with every answer, and each result writes mastery back to your graph.
Card 7 of 12MA 242 · EIGENVALUES
FRONTWhat equation gives the eigenvalues of A?
BACKdet(A − λI) = 0, the λ that makes A − λI collapse.
Forgot 110 minHard 21 dayEasy 34 days
SPACED REPETITION
Knows what to review, and when.
Forgot, Hard, Easy: ten minutes, a day, four days. Sapling schedules; you show up.
Lecture 7 · EigenvaluesSAVED
λ scales v, it never turns it.
Solve det(A − λI) = 0 for λ,
then null(A − λI) for the
eigenspace.
CONCEPTS EXTRACTEDEigenvaluesDeterminantNull space
SUMMARIZEEXTRACT CONCEPTSGENERATE QUIZ
NOTETAKER
Notes that think.
Write normally. Sapling summarizes, pulls the concepts, and links them to your graph.
MA 242→MIDTERM 2 · OCT 24
Eigenvalues & eigenvectorsYou missed 4 of 6 here
DeterminantsShaky on 3×3 expansion
Vector spacesSolid, light review
Built from 11 library docsREGENERATE
STUDY GUIDES
Built from your gaps.
Pick a course and an exam. The guide is assembled from your own library, weighted to weak concepts.
TUTORSOCRATIC · EIGENVALUES
I don't get why an eigenvalue is allowed to be negative.A negative λ flips v end-for-end while it scales it. Try A = [[−2,0],[0,1]] on v = (1,0). What comes back out?it points backwards. so λ = −2 flips and doubles it?HintI'm confusedSkipNEVER THE ANSWER
AI TUTOR
It asks. You answer.
Socratic, expository, or teachback. It never hands over the solution, it walks you to it.
OCTOBER · MONTH6 FOUND IN MA242_SYLLABUS.PDF
ExamPsetQuizProject
SYNCED · 6CALENDAR
A syllabus becomes a semester.
Upload once. Every exam, pset, and quiz is extracted, dated, and synced to Google Calendar.
91.2A−
MA 242 · SPRING 2026Psets40%94
Midterms35%88
Final25%—
Weights read from your syllabusGRADESCOPE · SYNCED
GRADEBOOK
Know your real grade.
Syllabus weights become categories. Every score rolls into a live grade and letter.
MA 242 Study RoomCODE · 7QK2
maya
YouThemBothNeither
maya is typingSTUDY ROOMS
Learn together.
Live rooms with chat and a side-by-side graph that shows exactly who knows what.
TUTORSOCRATIC · EIGENVALUES
I don't get why an eigenvalue is allowed to be negative.A negative λ flips v end-for-end while it scales it. Try A = [[−2,0],[0,1]] on v = (1,0). What comes back out?it points backwards. so λ = −2 flips and doubles it?HintI'm confusedSkipNEVER THE ANSWER
AI TUTOR
It asks. You answer.
Socratic, expository, or teachback. It never hands over the solution, it walks you to it.
OCTOBER · MONTH6 FOUND IN MA242_SYLLABUS.PDF
ExamPsetQuizProject
SYNCED · 6CALENDAR
A syllabus becomes a semester.
Upload once. Every exam, pset, and quiz is extracted, dated, and synced to Google Calendar.
91.2A−
MA 242 · SPRING 2026Psets40%94
Midterms35%88
Final25%—
Weights read from your syllabusGRADESCOPE · SYNCED
GRADEBOOK
Know your real grade.
Syllabus weights become categories. Every score rolls into a live grade and letter.
MA 242 Study RoomCODE · 7QK2
maya
YouThemBothNeither
maya is typingSTUDY ROOMS
Learn together.
Live rooms with chat and a side-by-side graph that shows exactly who knows what.
Honest answers
“Isn’t AI just going to do it forme?”
Fair question, and the one we get most. Sapling exists because we think AI should deepen understanding, not replace it. Here’s where we stand.
Still curious? Read the full FAQ
No, because Sapling never hands you the answer. It guides you toward the understanding: Socratic questioning, explanations you have to apply yourself, and TeachBack, where you do the explaining. Using Sapling is like having a tutor, not a ghostwriter. The work, and the learning, is still yours.
It won't, by design. Answer engines hand over the solution; Sapling walks you through the process and adapts to how you learn. If you paste a homework problem, expect guiding questions, not a finished answer to copy.
A general chatbot forgets you the moment you close the tab. Sapling maps what you know, remembers what you struggled with, schedules reviews before you forget, and grounds itself in your actual course materials. It's a study system, not a conversation.
We built Sapling to make you less dependent over time. Mastery only turns green when you can demonstrate understanding, and TeachBack literally requires you to explain concepts yourself. The goal is that you walk into the exam without us.
They stay yours. Uploads, notes, and messages are encrypted at rest (AES-256), used only to build your graph and study materials, and never sold or used to train outside models. Delete a document and its data goes with it.
Sapling is a study aid, the same category as flashcards, tutoring, or a study group. It doesn't produce submittable work. That said, every course sets its own rules, so check your syllabus; our stance on academic integrity is in the Journal.
Nothing during beta. Beta testers get every feature free while we build, and a say in what we build next. Join the list below and you're in line.
It can, which is why Sapling grounds answers in your uploaded course materials and shows its reasoning instead of just a verdict. You stay the judge. Spot an error? Flag it in one click and the tutor corrects course.
The Sapling Journal
The story of Sapling, as it grows.
Why we built it, where it’s headed, and what we’re learning about learning, written by the four of us, once a month.
Get the Journal, and a seat in the beta.
One letter a month while we build. First in the inbox, first on the tree when beta invites go out. No spam. We’re students too.
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