Content-driven vocabulary practice
Vocab Engine turns any word list into living prose — story blanks and hidden-word MCQs, a six-dimension mastery profile, and a five-factor schedule that resurfaces each word just before it fades.
The practice engine — type the missing word
The actual practice UI: per-letter feedback, progressive hints, live grading.
The method
Everything in Vocab Engine follows one loop: your content in, story practice, measurable mastery out. Each step is a small, honest surface.
01
{
"words": [
{ "id": "w-luminous",
"term": "luminous",
"definition": "full of light; glowing" }
],
"stories": [
{ "id": "s-keeper",
"title": "The Keeper of Last Light",
"body": "…{{blank:luminous}}…" }
]
}Paste or upload JSON — words, stories, MCQs. Five validation passes check it at the boundary before anything goes live.
02
Story blank · medium
“The dark room bloomed with a warm, luminous glow.”
Words appear as blanks inside real sentences, and as MCQs with the target word hidden. Every answer is graded instantly, letter by letter.
03
6 dimensions · 7 word statuses · recomputed every attempt
Each attempt recomputes a six-dimension profile. Progress is a number with receipts, not a streak.
Mastery
No green/red guesswork. Every word carries six weighted dimensions — accuracy, independence, flexibility, versatility, discrimination, durability — collapsed into one composite score and one honest status.
Composite score
0/100
Every attempt recomputes the whole profile — six weighted dimensions collapse into one composite that decides what you practice next.
Spacing
A five-factor multiplicative schedule — difficulty, format, history, consistency, performance — decides when each word resurfaces. Review lands just before forgetting would, and the gap between reviews widens as a word strengthens.
Your content
Import JSON — words, stories, MCQs. Five passes validate it at the boundary; content is immutable once live, and learner state stays append-only, so schedules survive every re-import untouched.
{
"words": [
{ "id": "w-luminous",
"term": "luminous",
"definition": "full of light; glowing" }
],
"stories": [
{ "id": "s-keeper",
"title": "The Keeper of Last Light",
"body": "…{{blank:luminous}}…" }
]
}1Syntax
valid JSON, required fields, no stray tokens
2Structural
words, stories and MCQs match their schemas
3Referential
every blank and tag resolves to a real word
4Pedagogical
blank density and difficulty pass learning checks
5Duplicate
no repeated ids, no accidental double imports
Begin
Import a handful of words, and the engine writes the practice around them. No setup, no decks, no busywork.