The building blocks that turn a photo of the exam into a sourced, auditable correction proposal: from the OCR token to the hash chain.
OCR / HTR (text recognition)
How does Laura recognise handwritten text?
OCR (for handwriting: HTR) turns image content into text. Laura runs several recognisers in parallel (local paths first, a cloud fallback only with consent) and reconciles them, instead of relying on a single recogniser. The result is evidence, not a fixed truth.
Concrete models can change; the glossary deliberately describes the multi-recogniser principle.
See also: Tokens (OCR tokens), Confidence cascade (4 stages), Evidence Layer
Tokens (OCR tokens)
What is an OCR token?
A token is the single-word representation of the recognition result: the recognised text plus its position in the image (bounding box), its confidence and its confidence class. Tokens are the smallest unit on which Laura hangs evidence, proposals and decisions.
See also: OCR / HTR (text recognition), Confidence class
Confidence cascade (4 stages)
How does Laura decide whether cloud AI is needed?
The confidence cascade works in four stages: first two local, free recognisers run and compare their result. If they agree confidently enough, the exam is finished for free and locally. Only the contested spots go to two independent cloud processes and are compared again. Whatever stays uncertain after that is not guessed but put to the teacher.
Free and local first, cloud only for the few doubtful cases, and only if the school allows it.
See also: Confidence class, Confidence traffic light
Assessment Object Model (AOM)
What is the Assessment Object Model?
The AOM is Laura's generic data model: Assessment → Submission → Evidence → Proposal → Decision → Output. It's deliberately not German-specific, so further subjects can plug in. It's the blueprint along which every task is processed and documented step by step.
See also: Submission, Proposal (assessment proposal)
Submission
What is a submission?
A submission is exactly one student's hand-in for an assessment: the second level in the data model. Attached to it are the recognised tokens, the proposals and the decisions of that one piece of work.
See also: Assessment Object Model (AOM)
Evidence of a decision
What does Laura store about a teacher decision?
For every decision Laura keeps several layers: the spot in the exercise book, the machine-recognised text, the text confirmed by the teacher, the confidence rating and the type of decision, plus the necessary supporting data. This makes it fully traceable later what a grade rests on and who made it. Nothing is left to memory or guesswork.
Every decision stays fully documented and reconstructable.
See also: Decision type, Traceable trail
Decision type
What kinds of decisions are there?
Every move you make gets a clear label: accept, correct it yourself, unreadable, doesn't belong or look at later. That label tells Laura exactly what you did with her suggestion. And it is the switch that steers learning: only certain deliberate decisions may change Laura's picture of a handwriting, a mere click-through does not.
This way Laura learns only from what the teacher has truly confirmed.
See also: Manual correction (Edit), Safeguard against wrong learning
Manual correction (Edit)
What happens when I correct a suggestion myself?
Sometimes Laura reads a word wrong. You simply type in the right version, and that's it. This one time is enough: Laura saves your correction and keeps an eye out for it when the same handwriting shows up again. All that matters is that something is actually there; from an empty field she learns nothing. So she only improves where you deliberately stepped in.
See also: Decision type, Handwriting learning (writer-adaptive recognition)
Unreadable decision
How do you mark a spot as unreadable?
With the unreadable decision, the teacher marks a token as not legible. A corrected text is excluded here; the decision flows into the handwriting profile as a negative signal. "Not legible" thus honestly stays that way, instead of being guessed.
See also: Decision type
Not-relevant decision
What does "not relevant" mean for a token?
"Not relevant" marks tokens that shouldn't flow into the handwriting profile: such as drawings, numbers or special characters. Laura thus only learns from real handwritten text and not from artefacts that say nothing for handwriting recognition.
See also: Decision type
Escalation (escalate)
What happens with an escalation?
With escalation, the teacher passes a conflict decision on to the school management. A meta event is created without a handwriting-profile update, and a justification is mandatory. Escalation is one of the governed paths when a conflict can't be resolved on the spot.
See also: Conflict resolution, Rationale
Merge-edit strategy
How does Laura resolve two contradictory correction states?
With the merge-edit strategy, the teacher types a new final text that replaces both contradictory states. A new edit decision results from it. No state is silently overwritten: the teacher deliberately sets the authoritative text.
See also: Conflict resolution, Manual correction (Edit)
Conflict resolution
What happens if the same exam was corrected on two devices?
Laura overwrites nothing silently, but asks the teacher which state applies. There are governed strategies: keep the local state, keep the server state, merge or escalate. The resolution thus stays a deliberate decision, with a trace.
See also: Merge-edit strategy, Escalation (escalate), Offline outbox
Tamper-proof chain
How does Laura ensure decisions aren't changed after the fact?
All log entries of a piece of work are linked together like the links of a chain: each entry carries a digital fingerprint of the one before. If someone altered an entry afterwards, the fingerprint would no longer match and the chain would break visibly. So it is immediately apparent whether the decision history has been tampered with.
Like a seal that tears at the slightest attempt to open it.
See also: Unchangeable log, GENESIS hash, Integrity status
Unchangeable log
What is an unchangeable log?
An unchangeable log is a record that can only be added to; changing or deleting is ruled out. Every correction decision is held in it like a stamp in a logbook that cannot be retouched away later. So the history stays honest and complete, even weeks on. What went in stays in, exactly as it was.
Like a logbook: entries are added, but never vanish.
See also: Traceable trail, Tamper-proof chain
Traceable trail
What is traceable in the course of a grade?
The trail is the continuous chain of all decisions, with time, acting person, fingerprint and reasoning. For every grade it can be traced who made it, when, and on what grounds. Nothing happens anonymously or in the dark; every step can be attributed. That is what makes a grade defensible to parents and heads alike.
Who, when, why: readable for every grade.
See also: Unchangeable log, Tamper-proof chain
GENESIS hash
What is the GENESIS hash?
The GENESIS hash is the fixed start value of a hash chain per submission: the "previous hash" of the very first entry. If it's missing, the chain isn't cleanly started; its constancy makes the start of every audit chain unambiguously verifiable.
See also: Tamper-proof chain, Integrity status
Integrity status
How does Laura show whether an audit chain is intact?
The integrity status sums up whether a submission's audit chain is valid or where it would be damaged: such as hash break, missing start, orphaned entry, duplicate identifier or quarantine. It's thus machine-detectable whether the data can be trusted.
See also: Tamper-proof chain, GENESIS hash
Offline outbox
What happens to decisions when there's no network?
The offline outbox is a small queue right in the browser: if the network drops, decisions are stored there and sent on automatically the next time there is a connection. So the teacher can keep working on the train or in the basement with no signal, without a single decision getting lost along the way.
Like an outbox that waits until there's a connection again.
See also: Idempotency, Conflict resolution
Idempotency
What prevents duplicate entries when resending?
Idempotency means: if the same decision is sent several times with the same identifier, such as after a connection drop, only one entry results anyway. A unique index prevents duplicates, so retries are safe.
See also: Offline outbox
Word diff (LCS)
How does Laura show what changed between two states?
The word diff uses the longest common subsequence (LCS) algorithm to make added and removed words visible in colour code. In the conflict view, the teacher thus sees at a glance how two correction states differ.
See also: Conflict resolution
A single source of truth
Why do no two places in Laura contradict each other?
Behind Laura sits the principle of a single source of truth: each kind of data is defined once, centrally, and everything else is derived from it. That way no contradictory copies can arise that drift apart over time. What is defined correctly once holds the same everywhere, one place of truth instead of many slightly differing notes.
Mirrored structure
What is a mirrored structure?
A mirrored structure is an order that looks the same in two places: once as a path through the web interface, and once as a filing in the folder structure. Both reflect the same hierarchy, so navigating and filing match one another. You find your way in the operation just as easily as in the storage.
Handwriting learning (writer-adaptive recognition)
How does Laura get better at handwriting she already knows?
The more often Laura sees a child's handwriting, the better she reads it. For each pupil she gradually builds a feel: which letters that child writes in their own way, where you tend to correct. This feel is fed only by your deliberate decisions, never by unconfirmed guesses of her own. Explained once, it sticks.
Ideally, a quirk only ever needs correcting a single time.
See also: Handwriting memory (WriterAtlas), Writer profile, Safeguard against wrong learning, Manual correction (Edit)
Safeguard against wrong learning
What keeps the handwriting knowledge from learning the wrong thing?
So Laura doesn't pick up bad habits, there's a bouncer at the door of learning. It only lets clean signals through: your real, deliberate decisions. A suggestion nobody checked, or two contradictory entries, don't get in. That way what Laura remembers about a handwriting always rests on what you truly confirmed, and doesn't get watered down over time.
See also: Handwriting learning (writer-adaptive recognition), Decision type, Handwriting memory (WriterAtlas)
Handwriting memory (WriterAtlas)
What does the handwriting memory store?
The WriterAtlas is Laura's memory for handwriting: for each child it records which letters they tend to mix up, which corrections keep coming up with them, and how confident Laura already feels about that script. It fills up solely from your deliberate decisions. That's why, ideally, you only have to explain a quirk once, after that Laura recognises it on her own.
See also: Writer profile, Handwriting learning (writer-adaptive recognition), Safeguard against wrong learning
Writer profile
What is a writer profile?
The writer profile is the page in the handwriting memory that belongs to exactly one child: the quirks of their script, from which Laura derives a reliable reading. It grows only through what you deliberately decide, never through silent guesses. Once learned, it is kept cleanly and applied again by itself on the same child's next piece of work.
See also: Handwriting memory (WriterAtlas), Handwriting learning (writer-adaptive recognition)
Careful technical rebuild
Is Laura being rebuilt in the background without the correction suffering?
Yes, and deliberately step by step. The proven correction engine, already tested on real exams, is being moved bit by bit into a cleaner, long-term structure. Until that move is complete, the tried-and-tested version stays the authoritative one. So it is a controlled relocation rather than a risky all-at-once switch.
Moving house while open for business: only move in once the new home really stands.
Runs right in the browser
Do I have to install anything for Laura?
No. Laura runs straight in the web browser: no installation, no update chores, no extra program on the school computer. You simply open the page and get going. That keeps use simple and fast, and it means Laura behaves the same, predictable way on any device, whether the laptop at home or the machine in the staff room.
No download, no admin appointment with IT: open the page and start.
XMP release metadata
How can you tell a PDF was released by the teacher?
Laura's exported PDFs carry an XMP metadata field that marks the teacher's release once finally confirmed. It's thus machine-verifiable that a document went through the full release path and isn't an intermediate state.
See also: No-Surprises PDF
Inline correction overlay
How do corrections appear on the digitised original?
The inline overlay places correction marks directly onto the digitised original, anchored at the position of the word concerned (bounding box). In adjust mode, the teacher can move markers so the correction sits exactly in the right spot.
See also: Correction marks, Tokens (OCR tokens)