The course, section and lesson model

Three objects, with a specific relationship. Understanding it prevents the two most common structural problems: lessons that never appear, and outlines that do not match the course.

The three objects

A course is the landing page and the container. It holds the description, the image, the access settings and the list of sections.

A section is a name, defined on the course. Sections are not content — they exist only to group lessons in the outline.

A lesson is the content. Each lesson is attached to one course and to one section of that course.

The relationships that matter

Course
 ├─ Section "Introduction"
 │    ├─ Lesson (order 1)
 │    └─ Lesson (order 2)
 └─ Section "Module 1"
      ├─ Lesson (order 3)
      └─ Lesson (order 4)

Two rules follow, and both are absolute:

• A lesson with no attached course has no page to belong to, and its URL returns a not-found result.
• A lesson with no attached section does not appear in the course outline, even though it is published and its URL works.

The lesson list's Section column makes the second rule easy to audit: a dash means the lesson is invisible in the outline.

Order comes from the lesson

Sections are ordered by the list on the course. Lessons are ordered by their order attribute, which you set on the lesson.

That same order drives:

• the outline in the course sidebar;
• the previous/next navigation between lessons;
• the lesson list in the administration.

Use spaced values — 10, 20, 30 — so a lesson can be inserted later without renumbering everything.

Sections are per course

The section list belongs to one course. Two courses with a section called Introduction have two unrelated sections.

That is why a lesson's section selector is built from the course you attached it to: choose the course first, save, then choose the section.

How many sections

Three to six for most courses.

• Fewer than two — the outline is a flat list, and the accordion adds nothing.
• More than about eight — students scroll past sections rather than reading them.

Name them the way a student would describe the course to someone else, not the way the material is filed internally.

Deleting a section

Removing a section from the course leaves any lesson assigned to it pointing at something that no longer exists — so those lessons disappear from the outline.

Before deleting a section:

1. Filter the lesson list and note which lessons use it.
2. Reassign them to another section.
3. Then remove the section.

One lesson, one course

A lesson belongs to a single course. To use the same material in two courses, create two lessons.

That duplication is deliberate: each copy can have its own section, order, preview flag, permission override and estimated time — and each course's progress is counted independently.

Progress counts every lesson

A course's completion percentage is calculated from all lessons attached to the course, whether or not they are assigned to a section.

So an orphaned lesson — attached to the course but with no section — is invisible in the outline and still counted in the denominator, which is why students can find themselves unable to reach 100%.

Keeping the Section column free of dashes prevents it.

Verify a course's structure

1. Open the lesson list and filter mentally by course.
2. Confirm every lesson shows a course and a section.
3. Confirm the order values produce the sequence you want.
4. Open the course and read the outline.
5. Confirm the outline matches the plan you wrote.