Shape: lesson

A lesson or a course chapter, written to be studied alone. It states what the learner will be able to do, explains it and corrects the usual wrong idea; then it checks each aim with a question whose answer stays folded until tried.

Skeleton

# <The subject, named as the field names it>

> One or two sentences that stand for the lesson: what it teaches and why it matters.

**Shape:** [lesson](<link to this file>).

## Objectives          few, each with an id and an observable verb
- **O1** Compute ...
- **O2** Explain why ...

## Terms               each term bold where it is defined, with its definition

## <Part 1>            the explanation, figure first when the content is a relation;
                       a Trap box where learners hold a known wrong idea
> **Trap:** <the wrong idea, as learners hold it>
> **Why not:** <why it is wrong, then the accepted idea>

### Check yourself     the question block of this part, each item tagged by an objective
1. **O1** <question>
   <details><summary>Answer</summary> the answer, then why </details>

## Key points          the objectives restated as what the learner can now do

## See also            the notes, sheets and decks that go with it

The blocks

Block	Rule	Grade	Evidence
Title, summary	the topic's two first blocks; the summary is the overview read before any detail	measured for an overview; the form is a convention	topic; overview first
Objectives	few, each with an id and a verb a test can observe	measured that objectives direct study to what they name; the verb rule is a convention	instructional text, strand 3
Terms	defined at first use, bold	supported with caveat	the core note; define before use
Trap	the wrong idea stated, marked wrong, then the accepted idea	measured: refutation text beats expository text, g = 0.36 over 30 comparisons; whether it lasts is unsettled	instructional text, strand 5
Check yourself	per part, items tagged by objective, answers folded	measured for retrieval (core); the tagging is a convention	question block
Key points	at the end, restating the objectives	supported with caveat for the place: an end summary beat an opening one on the same page in two small studies; restating the objectives is a convention, untested	instructional text, strands 4 and 8
See also	links, never copies	convention	topic

Alignment is the rule that ties the blocks: every objective is tested by at least one question, and every question tests a stated objective. It is the practice of every template read (OpenStax, the Carpentries, course rubrics), and no controlled trial of it was found (position).
Not in the shape: a glossary at the end (the weakest gloss form, in second-language studies), and a crib sheet as a learning aid (making one does not teach): against.

How it derives from the topic

Topic block	Here	Change
Title	the subject	none
Summary	the quoted line under the title	none
Body	Objectives, Terms, the parts, Key points	Objectives, Trap and Key points added to the core note
Contents	none: a lesson holds no topics	left empty
See also	See also	none
(metadata)	the Shape line	names this shape, as the topic asks

Checked by

Check	What it verifies	Kind
`lesson`	every objective is tested; every question names an objective that exists	exact
`lesson`	every question has a folded answer	exact
`lesson`	every Trap, a quote or a callout titled Trap, holds a Why not	heuristic, a warning: a refutation written in prose carries no label
`lesson`	an answer gives a reason, not only the key; multiple-choice items follow the question block	heuristic
standard	the headings Objectives, Check yourself, Key points, See also	exact

An example that passes every check: binary search.