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Tessera Access is accessibility built into authoring and learning, not a separate audit run afterward. It checks lessons as they’re written, checks uploaded documents when they’re scanned (automatically the first time someone opens a file’s report), and blocks a lesson from publishing when it doesn’t meet the institution’s policy.

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Scores and grades

Every accessibility report — a lesson, a file, a course, or an institution — carries a score from 0 to 100:
Penalties by severity: critical 30, serious 15, moderate 8, minor 3. Three or more of the same issue count as three, so one severe, recurring problem doesn’t sink the score past the point of being useful feedback. The score maps to a grade: A course’s or institution’s score is the average of its parts’ scores.

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What’s checked

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Lessons and assignment instructions

Tessera’s lesson content is a list of typed blocks, so these checks run directly against the block model — instantly in the editor, and again at the publish gate:

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PDF files

Checked in the Worker against the document’s real structure, not just its visible text:

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Word documents

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PowerPoint files

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Fixes

Every fix — alt text, a marked table header row, corrected title or language metadata, or OCR — saves a new version of the document. The original is never overwritten; every version is kept. AI-suggested fixes (an alt text description, a plain-language rewrite, a clearer link name) are drafts, the same rule that applies to every other AI output in Tessera: a person reviews and keeps a suggestion before it takes effect. An unreviewed AI draft blocks publishing, but it does not itself count against the accessibility score — the score reflects the content’s actual state, not whether a draft is pending review. Alt text can be written into Word and PowerPoint files. For PDFs, Tessera doesn’t yet write alt text into the file or extract its images for AI suggestions; the fixes it applies to PDFs are title, language, and OCR. The reading version and e-book carry a document’s text and headings, not its images.

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Accessible formats

Every PDF, Word, and PowerPoint file gets a menu of accessible formats, generated on first request and cached per version:
  • Reading version — the extracted content rendered as a plain, accessible page.
  • E-book (ePub 3).
  • Audio — a synthesized read-through.
  • Searchable version — for a scanned PDF with no extractable text, OCR produces a searchable copy so screen readers and search both work. See OCR for scanned PDFs below.

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OCR for scanned PDFs

A scanned PDF has no text layer for a screen reader to read or for search to index. Running OCR on it is both a fix — it saves a new, searchable version of the file — and an accessible format in its own right, since the reading version, e-book, and audio of a scan are built from the OCR text.

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Publishing policy

Administrators set two things that the server enforces, not just the editor screen:
  • A minimum accessibility score a lesson must meet to publish.
  • A list of blocking severities — for example, treating any critical or serious issue as a publishing block regardless of the overall score.
An instructor sees exactly why a lesson can’t publish: the score, the policy’s threshold, and which issues are blocking.