Rubrics and model answers

Objective questions have an answer key. A long_answer question needs something more: a rubric (named criteria, each worth part of the marks) or a model answer (the answer an examiner would accept), or both. Rubrics and model answers apply to long_answer questions in both handwritten and typed exams.

Send a rubric or a model answer for every long-answer question before the first submission. It is the single biggest factor in marking quality and consistency.

The rubric object

{
  "partial_marking": true,
  "instructions": "UPSC GS2. Judge content, structure and balance. Do not reward length beyond the word limit.",
  "criteria": [
    {"name": "Introduction", "marks": 2, "keywords": ["Article 356", "federalism"],
     "guidance": "Defines the issue in context; a fact or judgment helps."},
    {"name": "Dimensions covered", "marks": 6, "keywords": ["S.R. Bommai", "Sarkaria", "Punchhi", "Governor"],
     "guidance": "Constitutional, judicial, political and administrative dimensions; credit each well-argued dimension."},
    {"name": "Examples and data", "marks": 3, "keywords": ["1994", "President's Rule"],
     "guidance": "Specific cases, commissions, data."},
    {"name": "Way forward", "marks": 2, "keywords": ["inter-state council", "guidelines"],
     "guidance": "Concrete, balanced suggestions."},
    {"name": "Conclusion and presentation", "marks": 2, "keywords": [],
     "guidance": "Ties back to cooperative federalism; legible structure, headings, flow."}
  ]
}

This is a rubric for a 15-mark question: its criteria add up to 2 + 6 + 3 + 2 + 2 = 15.

boolean

default:"true"

Whether a criterion can earn part of its marks.

string

Instructions for this question, up to 4,000 characters.

object[]

required

1 to 30 criteria.

Show criterion

string

required

Up to 200 characters, unique within the question (ignoring case). Cannot contain < or >. Results report marks per criterion under this exact name.

number

required

Greater than 0. All criteria together must equal the question’s max_marks.

string[]

Up to 30 terms the answer is expected to use, each 1 to 100 characters.

string

What earns this criterion, up to 2,000 characters. No mark figures: see below.

Validation rules

Rubrics are checked when you send them, so a wrong rubric never silently changes how a paper is marked.

Rule	Error
Criterion marks add up exactly to the question’s `max_marks`.	`422 rubric_marks_mismatch`, with `details.question_label`, `details.criteria_total` and `details.max_marks`
Criterion names are unique within the question (ignoring case).	`422 rubric_duplicate_criterion`, with `details.question_label` and `details.criterion`
Guidance contains no mark figures.	`422 rubric_guidance_has_marks`, with `details.question_label` and `details.criterion`
Shape: at least one criterion, at most 30; `name` and `marks` present; `marks` > 0; length limits.	`422 validation_failed`, with `details.errors[]`
A criterion worth a non-multiple of 0.5 (for example 1.25).	Accepted, with warning `rubric_marks_not_half_step`; final marks are rounded to 0.5
Rubrics only on `long_answer` questions.	`422 validation_failed` (field code `not_allowed`)

{
  "error": {
    "code": "rubric_marks_mismatch",
    "message": "Criteria for question 3(a) add up to 4, question max is 5.",
    "request_id": "req_01J9X2...",
    "details": {"question_label": "3(a)", "criteria_total": 4, "max_marks": 5}
  }
}

Keep marks out of guidance

Marks belong in criteria[].marks only. If guidance also mentions marks, the grader gets two sources of truth that can disagree. The check refuses:

A number followed by mark, marks, mk, point, pts and similar: “2 marks”, “1.5 points”.
A number word followed by mark(s): “half marks”, “full marks”, “two marks”.
An awarding verb (award, give, deduct, allot, allocate, assign, grant, cut) followed by an amount: “award 1”, “give half”, “deduct one”.
The signs ½, ¼ and ¾.

Bare numbers are fine, so “Article 356”, “Section 80C”, “the 1994 judgment” and “two dimensions” all pass.

Refused
Accepted

{"name": "Balanced equation", "marks": 2,
 "guidance": "Award 1 mark for correct formulae and 1 mark for balancing."}

[
  {"name": "Correct formulae", "marks": 1,
   "guidance": "All reactants and products written with correct chemical formulae."},
  {"name": "Balanced", "marks": 1,
   "guidance": "Atoms of each element equal on both sides."}
]

Phrases like “give full credit” also match the check, because “give” is followed by “full”. Write “credit if the student names glucose” instead.

Model answers

A model answer is plain text, up to 20,000 characters: the answer an examiner would accept, with the points that earn marks. You can send it on its own or alongside a rubric.

{
  "label": "21",
  "type": "long_answer",
  "max_marks": 2,
  "text": "Why is respiration considered an exothermic reaction? Explain.",
  "model_answer": "During respiration, glucose is oxidised in the cells to carbon dioxide and water. This process releases energy, which is why respiration is an exothermic reaction."
}

Without a rubric

You send	What happens
Rubric (with or without a model answer)	The grader marks against your criteria. `GET /exams/{id}/rubrics` shows `source: "partner"`.
Model answer only	The grader uses your model answer as the reference answer.
Neither	Accepted, with an `auto_rubric` warning. On the first copy, a rubric is generated from the question text and then reused for every candidate, so marking stays consistent. It shows as `source: "generated"`.

A generated rubric is consistent, but nobody has reviewed it. Read it with GET /exams/{id}/rubrics after the first copy, and replace it with your own if needed.

Set rubrics and model answers

You can send rubrics and model answers inline with each question on POST /exams or POST /exams/{id}/questions. To change them later, use one of the endpoints below. They work in draft and after open, until the exam is finalized.

One question: PUT
Many questions: PATCH

PUT /exams/{id}/questions/{question_id}/rubric

curl -X PUT https://api.evalezy.com/v1/exams/$EXAM_ID/questions/$QUESTION_ID/rubric \
  -H "X-API-Key: $EVALEZY_API_KEY" \
  -H "Content-Type: application/json" \
  -H "If-Match: 4" \
  -d '{
    "rubric": {
      "partial_marking": true,
      "criteria": [
        {"name": "Oxidation of glucose", "marks": 1, "keywords": ["glucose", "oxidation", "CO2"],
         "guidance": "Mentions breakdown or oxidation of glucose."},
        {"name": "Energy released", "marks": 1, "keywords": ["energy", "exothermic"],
         "guidance": "States that energy is released."}
      ]
    }
  }'

Response:

{
  "version": 5,
  "question": {"id": "d9a4...", "label": "21", "type": "long_answer", "max_marks": 2.0,
               "rubric": {"partial_marking": true, "criteria": [...]}, "model_answer": "..."}
}

PATCH /exams/{id}/rubrics sets rubrics and model answers for up to 200 questions in one call, with a single version bump.

curl -X PATCH https://api.evalezy.com/v1/exams/$EXAM_ID/rubrics \
  -H "X-API-Key: $EVALEZY_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "questions": {
      "d9a4...": {"model_answer": "Glucose is oxidised to CO2 and water, releasing energy."},
      "f310...": {"rubric": null},
      "a77c...": {"rubric": {"criteria": [{"name": "Diagram", "marks": 3}, {"name": "Labels", "marks": 2}]}}
    }
  }'

The response carries version and the updated questions[].

Each question’s change is {"rubric": {...} | null, "model_answer": "..." | null}:

Key left out: that part is left as it is.
null: that part is deleted.
Value: that part is replaced.

At least one of the two keys is required. Each rubric is checked against its question’s current max_marks. You can also set or clear a rubric with PATCH /exams/{id}/questions/{question_id} and a rubric or model_answer field.

Versions and If-Match

Every accepted change bumps the exam’s rubric version. Each result records the rubric_version it was graded with, so you can tell which results were graded before a change. To avoid overwriting someone else’s edit (for example, a teacher editing the same rubric in the dashboard), send If-Match: <version> with the version you last read:

Read the current version with GET /exams/{id}/rubrics.
Send your change with If-Match: 4.
If the rubric is no longer at version 4, you get 412 rubric_version_mismatch with details.expected and details.current. Re-read, merge and retry.

If-Match takes a plain number (4, "4" and W/"4" are all accepted). Anything else returns 422 validation_failed. An exam with no stored rubric yet is at version 0.

Sync status

Changes are saved straight away and then delivered to the grader. Usually that takes a moment and the response carries the new version. If delivery is delayed, the response carries "version": null, "sync": "pending", and delivery is retried automatically every minute. While changes are pending, a write with If-Match returns 412 rubric_version_mismatch, because the current version isn’t known yet. Retry shortly. If the grader refuses a change that was already accepted, GET /exams/{id}/rubrics shows "sync": "failed" and a sync_error object listing the affected question_ids. Set those questions’ rubrics again to clear it.

Read rubrics

GET /exams/{id}/rubrics (scope evaluation:read) returns every question’s rubric and model answer, with changes that are still syncing already applied:

{
  "version": 5,
  "locked": false,
  "locked_at": null,
  "questions": [
    {"question_id": "d9a4...", "label": "21", "source": "partner", "state": "draft",
     "rubric": {"partial_marking": true, "criteria": [...]},
     "model_answer": "Glucose is oxidised...", "updated_at": "2026-10-02T09:20:11Z"},
    {"question_id": "e51b...", "label": "33", "source": "generated", "state": "draft",
     "rubric": {"partial_marking": true, "criteria": [...]}, "model_answer": null, "updated_at": "..."},
    {"question_id": "f310...", "label": "34", "source": "none", "state": "draft",
     "rubric": null, "model_answer": null, "updated_at": "..."}
  ]
}

source is partner (you set it), generated (created from the question text) or none. If the grader is briefly unreachable, this call returns 503 engine_unavailable with Retry-After: 30.

Rubric generation on request and rubric locking are on the roadmap. Until then, write rubrics yourself, or let the first copy generate them and review them afterwards.

Errors

Status and code	When
`422 rubric_marks_mismatch`	Criterion marks don’t add up to the question’s `max_marks`.
`422 rubric_duplicate_criterion`	Two criteria in the same question have the same name.
`422 rubric_guidance_has_marks`	Guidance mentions marks.
`422 validation_failed`	Shape problems, a non-`long_answer` question, a bad `If-Match` value, or an empty change.
`412 rubric_version_mismatch`	`If-Match` doesn’t match the current version, or earlier changes are still syncing.
`409 rubric_locked`	The exam’s rubric is locked.
`409 exam_finalized`	The exam is finalized.
`404 question_not_found`	A question id isn’t in this exam.
`503 engine_unavailable`	The grader is briefly unreachable (reads only). Retry after the `Retry-After` interval.

Get started

Concepts

Guides

Platform

Rubrics and model answers

The rubric object

Validation rules

Keep marks out of guidance

Model answers

Without a rubric

Set rubrics and model answers

Versions and If-Match

Sync status

Read rubrics

Errors

​The rubric object

​Validation rules

​Keep marks out of guidance

​Model answers

​Without a rubric

​Set rubrics and model answers

​Versions and If-Match

​Sync status

​Read rubrics

​Errors

The rubric object

Validation rules

Keep marks out of guidance

Model answers

Without a rubric

Set rubrics and model answers

Versions and If-Match

Sync status

Read rubrics

Errors