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Content quality

How every question and lesson is verified before your child ever sees it.

The core principle

Content generation is restricted to approved curriculum source material, and questions must cite supporting sources before publication. Computations are verified by code, not by AI alone. Child-facing content is only published after it passes the required checks.

The six-stage pipeline

Every piece of content passes through six sequential checks.

  1. 1

    RAG generation

    Questions are generated using only curriculum-approved source material retrieved from a knowledge base. Content generation is restricted to approved sources, and each question must cite the material it draws from.

  2. 2

    Code verification

    All mathematical and scientific calculations are verified by code: SymPy for maths, Pint for physics, ChemPy for chemistry, a local periodic table for element facts. If the calculation is wrong, the question fails.

  3. 3

    Consensus check

    A second independent AI pass reviews the question at zero temperature and confirms the answer is correct, unambiguous, and at the right difficulty level.

  4. 4

    Constitutional critique

    A third pass checks the question against a written constitution covering age-appropriateness, cultural sensitivity, distractor plausibility, hint progression quality, and single-answer clarity.

  5. 5

    Semantic deduplication

    The question is compared against all existing published questions in the same topic. If it is too similar to an existing question, it is rejected to ensure children see a variety of questions.

  6. 6

    Confidence scoring and decision

    A weighted score is calculated across all checks. Content must meet a subject-specific confidence threshold before it is published. Maths requires 85% or above; English comprehension and Biology require 90% or above.

Verification by subject

Different subjects use different verification tools. AI generates and explains; code verifies.

Maths (arithmetic)Safe-eval whitelist: arithmetic is computed directly, not estimated.
Maths (algebra)SymPy: symbolic mathematics solver.
PhysicsPint (units) + SymPy: unit-aware calculation checking.
ChemistryChemPy + local periodic table: element facts are checked against a fixed reference, not generated.
English grammarLanguageTool (en-GB): grammar rule enforcement.
English comprehensionSource grounding: answers must cite curriculum source chunks.

Content status

Every piece of content carries a status. Only published content is ever shown to children.

publishedPassed all pipeline checks. Visible to children.
stagedPassed structure checks but below the confidence threshold. Not visible to children.
flaggedLive monitoring detected a high error rate or hint misuse. Removed from child-facing pool and queued for regeneration.
regeneratingCurrently being reprocessed through the pipeline after being flagged.

What is currently available

Maths content for Year 3 and Year 7 is the most complete. English and Science content is progressively expanding: topics are published only once they have passed the full pipeline. Your child will only ever see content that is ready.

New topics and subjects are added as they clear all quality checks. The pipeline runs continuously, so the range of available topics grows over time without any code changes.

Ongoing monitoring

Every night, an automated check reviews all published questions. If a question has a high error rate (more than 60% of children getting it wrong) or high hint-3 usage (more than 50% of attempts using the biggest hint), it is automatically flagged and removed from the child-facing pool.

Flagged questions are sent back through the pipeline for regeneration. A child will never encounter a question that has been identified as consistently confusing.

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