Exams

A checkpoint is an exam: a set of questions of its own, the way a university publishes one. The interface calls them by the checkpoints label of the domain, so a domain that sets checkpoints: Exams shows Exams (The root and the domain).

A checkpoint is not made of flashcards. Its questions are not flashcards, and the scheduler never sees them.

Where checkpoints live

The checkpoints of a domain live in its checkpoints/ directory, beside its sections. Inside it, use directories to any depth: one per university and one per year under it, for example.

phy/
├── index.md
├── eam/                                  a section
└── checkpoints/                          the checkpoints of the domain
    ├── index.md                          a checkpoint folder: order
    └── eam/                              a checkpoint folder
        ├── index.md                      title, order
        ├── direct-current-quantities.md  a checkpoint
        └── dc-analysis-laws.md           a checkpoint

checkpoints/ and each directory under it is a checkpoint folder. Each needs an index.md.
Each .md file in a checkpoint folder, other than index.md, is a checkpoint.
A checkpoint folder can hold checkpoints and other checkpoint folders side by side.
The order of the domain does not list checkpoints.

A checkpoints/ directory without its index.md is an error:

ERROR ./math/checkpoints/index.md: cannot read: no such file

A checkpoint folder must hold at least one checkpoint or one folder.

A checkpoint folder

---
title: Electromagnetism
order: [direct-current-quantities, direct-current-circuits, dc-analysis-laws, dc-analysis-methods, dc-analysis-thevenin]
---

Field	Is
`title`	the name of the folder; its id if absent
`order`	the checkpoints and the folders it holds, in order
`draft`	`true` holds back the folder and everything in it

order follows the same rules as everywhere else (The tree).

A checkpoint

---
title: Physics, 2020
---

Answer every question without notes.

::: question q1
A 9 V source feeds a 3 Ω and a 6 Ω resistor in series. What is the current?

::: answer
1 A.
:::

::: solution
The resistances add: $9 / (3 + 6) = 1$ A.
:::
:::

::: question q2
A component carries 0.5 A when 6 V sits across it. What is its resistance?

::: answer
$R = V / I = 6 / 0.5 = 12\ \Omega$.
:::
:::

Part	Written as
the title	`title:` in the front matter; the id if absent
the instructions	the text outside the questions
a question	a `::: question` block, with an `::: answer` and an optional `::: solution`

Put the instructions before the first question. The app shows all text outside the questions as the instructions, at the top of the checkpoint.

A question is written exactly as a flashcard of a deck (Flashcards and solutions). Its answer is required, and its solution is optional. A question without an id takes e1, e2, in order. Two questions in one checkpoint cannot share an id.

A checkpoint holds questions and nothing else. A card, a figure or a reference in a checkpoint is an error:

ERROR ./math/checkpoints/mit/2020.md:5: `card` cannot sit inside `checkpoint`

The instructions and the questions can link references of the domain with [label](reference:id).

A checkpoint draws no plot. A plot block in the instructions or in a question is an error:

ERROR ./math/checkpoints/c.md:7: a `plot` block draws only in a `card` or a `figure`, and this one sits in the instructions of a checkpoint, so the app never draws it: move it to a card

Ids

The id of a checkpoint is its filename stem, and the id of a folder is its directory name. The rules of unique ids and reserved ids do not apply to them. Two folders can each hold a 2020.md, because the address of a checkpoint in the app includes its folders.

What the learner sees

The Exams scroll shows the checkpoints of the domain one after another, in the order of their folders. A checkpoint with no questions does not show. A checkpoint shows its instructions, then its questions, each with its number. The app marks a question as read when it crosses the reading line, so a checkpoint has a progress mark, as a deck has.

The head of each checkpoint has a reveal control. It shows the answer and the solution under each question, and hides them again.

A domain needs at least one deck. The checker refuses a domain with checkpoints and no deck (The root and the domain).