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Lecture Ingestion

Lecture ingestion sends your lecture materials to Iris's knowledge base, enabling it to answer student questions based on your actual course content rather than general knowledge alone.

What Gets Ingested​

When you ingest lectures, Iris processes:

  • Slide content — text and structure from attachment units (PDFs, slide decks)
  • Video transcriptions — if available, transcriptions from video units

This content is indexed and made available to Iris so it can reference specific slides, concepts, and explanations from your lectures when responding to students.

How to Ingest Lectures​

There are two ways to send lecture content to Iris:

Bulk Ingestion​

On the lecture management page, use the "Send All Lectures to Iris" button to ingest all lecture units at once. This is the fastest way to set up Iris for a course with existing materials.

Individual Ingestion​

On an individual lecture unit that has attachments, use the "Send Unit to Iris" button to ingest just that specific unit. This is useful when you add or update a single lecture.

Prerequisites​

Before ingesting, ensure that:

  • Lectures have attachment units — Iris can only ingest content from lecture units that have attached files (slides, PDFs). Lectures without attachments have nothing to ingest.
  • Iris is enabled for your course — see Enabling Iris

When to Re-Ingest​

You should re-ingest lectures when:

  • You update slide content — Iris uses the version it last ingested, so updates require re-ingestion
  • You add new lectures — newly added lectures are not automatically ingested
  • You add transcriptions — if video transcriptions become available after the initial ingestion
tip

Make it a habit to re-ingest after updating lecture materials. A quick click on "Send Unit to Iris" ensures students always get answers based on the latest version of your content.

Re-Ingesting While a Unit Is Still Processing​

You do not have to wait for a running ingestion to finish before sending the same unit again. Iris supersedes the run in progress: the older run stops at its next checkpoint and sends no final success or failure status. It may already have sent progress updates before it was superseded.

This is what makes correcting a mistake cheap. If you replace the slides again, or fix a video link while the first version is still being transcribed, the obsolete run does not finish and cannot overwrite the result of the one you actually want.

Iris stops a superseded run at a checkpoint and guards the write phases of the current run. Before reporting ingestion as finished, it verifies the stored content. During processing, old and new entries can briefly coexist, so wait for ingestion to finish before relying on answers about the updated material.

How Iris Uses Lecture Content​

Once ingested, Iris draws on your lecture materials when answering student questions. A chat set to a specific lecture retrieves from that lecture, and a chat at course level retrieves across all of them. When Iris uses a slide or a passage from a recording, it attaches a citation marker to the sentence it supports, and a student clicking that marker lands on the cited page or video moment.

This is particularly valuable because it means Iris does not rely solely on its general training data. It can answer questions specific to your course — including topics covered in a unique way, institutional conventions, or domain-specific terminology you use in your lectures.

Slide Page Numbers in Answers​

Iris reads the number printed on each slide during ingestion and refers to slides by that number, not by their position in the PDF. For a deck with a title or agenda slide in front, the two differ, and the printed number is the one your students see.

Where the printed numbering is regular, Iris infers the number of an unreadable slide from its neighbours, so a single unnumbered or misprinted slide in an otherwise consistent deck still gets named correctly.

Two cases fall outside that:

  • No number anywhere in the deck. If Iris cannot read a single page number — unnumbered slides throughout, or a scan it cannot make out — it falls back to counting PDF pages and names slides by that count. For a deck with a title slide in front, those numbers are one ahead of what students would have read off the slides, had there been numbers.
  • A slide whose number stays unknown. Where the rest of the deck is numbered but one slide's number cannot be resolved — typically front matter before printed page 1 — Iris describes it without a number ("the slide on quicksort") rather than guessing.

Adding page numbers to your slides is therefore the surest way to get Iris to refer to them the way your students do.

What Replacing Slides Does to Older Citations​

Replacing slides or a video does not retroactively change answers students have already received. A citation or a position from an older answer still opens the lecture unit, but it does not jump to the old page or moment, because that position may now refer to different content. Once the new material has finished processing, a fresh question produces citations into it.

Next Steps​