Watch a good lecturer teach a room and, every few minutes, they turn round. A table goes up, two boxes and a line, a word underlined twice. The students copy it down while the explanation carries on. That board is half the lesson, and it is the half a recorded lecture loses: in front of a camera, the lecturer describes the table instead of drawing it.
Classroom Board puts it back. Where a teacher would have turned to write, the screen becomes a board, and the table, diagram or definition is written on it stroke by stroke, by a pen that moves, on the word the lecturer says. Nothing on the board slides, fades or zooms in as a finished picture.
The clips below come from a sixteen-minute undergraduate database lecture on mapping cardinality, recorded on a green screen. On the left is the camera file exactly as it was recorded. On the right is the finished lecture at the same moment.
1. A table, the way a teacher draws one
The lecture opens on a story: a student portal, and what happens to the student table when every student can pick a course. In the raw file the lecturer explains it in words. In the finished lecture, the table is ruled up on a blackboard and filled in as she gets to each column.
“… he adds one extra column to the student table … the record of the course this student is taking …”
“One column, one course”: the heading, the rules of the table, then each column and row as she names it.
The board is the whole screen here, and that is deliberate. A student copying a table down needs to see all of it, at a size they can read; a board shrunk into a corner beside the lecturer is a board nobody can copy. The lecturer comes back as soon as the writing is done.
2. A diagram, built line by line
The core of the lecture is the four ratios that relate two entity sets. Each one is a small ER diagram, and each is drawn as she explains it: the two boxes, the line between them, the 1 and the N at either end, and the verb that names the relationship.
“One-to-one, written 1:1 … one faculty member heads at most one department … One-to-many, 1:N.”
“Four ratios”: Faculty heads Department, 1 to 1; then Department employs Employee, 1 to N, drawn underneath.
What goes on the board is checked against the subject, not copied from the speech. A recorded sentence can slip — a ratio said the wrong way round, a term half-finished — and the student will copy whatever is written. So every page is checked against the lecturer’s script and the discipline before it is drawn. Where the two disagree, the board is the correct one.
3. Whiteboard or blackboard, chosen by the screen around it
Later the lecture turns to participation: whether every loan must have a borrower. This page appears in a chapter whose ground is dark blue, and a blackboard on a dark ground disappears, so the board is a whiteboard with markers instead.
“Take the classic bank example … the loan has total participation … Customer has only partial participation.”
“Total and partial”: Loan, taken by, Customer — the double line drawn for total, the single line for partial.
That photograph is the other half of the rule that the board is an addition. The deck keeps its effects and the photographs and clips keep their places. A photograph is only allowed where the pen is idle — never over writing in progress, and never over a board arriving or leaving.
How the engine decides
Find where a teacher would turn to write. A table, a diagram, a definition, a worked step: the passages where the spoken explanation is describing something a student would want drawn. The rest of the lecture is left to the presenter and the deck.
Write the board, not the transcript. A short title, one diagram or table, a handful of labels. About 45 words a page at most, in writing large enough to copy. Where a passage needs more, it becomes two boards in sequence rather than one crowded one.
Anchor every stroke to a word. Each heading, row and line is tied to the words that introduce it in the recording, so the pen writes it as it is said. A board that runs ahead of the lecturer is as wrong as one that lags.
Check it for accuracy. Every page is checked against the lecturer’s script and the subject. The board is the version a student will copy, so it has to be right even where the spoken sentence slipped.
Give it the screen, and give it back. A board has the whole screen while it is being written. Where it would sit finished for a long stretch, the screen goes back to the lecturer or the deck. The lecturer still has their share of the lecture; boards do not crowd them out.
Keep the course’s look. The board hangs below the corner logo and never covers it, and the strip above it takes the chapter’s ground colour. Short drawn scenes elsewhere in the lecture use the same pen in the course’s own template style — its typeface, its colours, no board at all.
What it does not do
Write what a teacher would
- Draw tables, diagrams and definitions stroke by stroke, on the word
- Choose blackboard or whiteboard from the screen around it
- Keep the captions on the board, clear of the writing
- Leave the deck, photographs and clips in their places
Replace the lecture with a slideshow
- Paste in a finished picture and call it a board
- Write out the sentences the lecturer is speaking
- Crowd a page: past about 45 words it becomes two boards
- Leave a finished board on screen with nothing happening
What it came to on this lecture
| Measure | This lecture |
|---|---|
| Board pages | 10 — 8 blackboard, 2 whiteboard |
| Time on the board | 5 min 42 s of a 16 min 15 s lecture |
| Shortest and longest page | 17 s and 55 s |
| Elements arriving as a finished picture | none — every line is drawn |
| Captions or photographs over writing in progress | none |
A recorded lecture loses the board first. Putting it back, written on the word, is the closest a video gets to the moment a student looks down and copies it out.
Classroom Board sits alongside the rest of the pipeline: cleanup, captions, Quick Checks and the welcome and closing cards. For lectures recorded without a green screen, see how the engine edits the lecturer where they stand; for the cleanup that runs first on every lecture, see the part of the recording no student should hear.
Send us a lecture where the lecturer explains a table or a diagram in words, and we will send it back with the board written in, on the word. Send a lecture →