ARFC-1013: Scope and Sequence Structure

Status

Draft Draft Date: 2026-08-08 Last Call Date: — Publication Date: — Version: 0.1

Abstract

A scope and sequence is a teacher’s plan for a course: what will be covered, grouped into units, in the order they intend to teach it, fitted into the time available. Teachers build one for every course they teach, rebuild it every year, and today the platform cannot hold it. A planning document can be authored, but nothing else can read it — it is attached to no course, no lesson can be linked to it, and no report can be built from it.

This ARFC specifies the plan as a first-class part of a course. Scope — the objective set — is established by ARFC-1011. This document specifies sequence: units that collect related lessons, the objectives each unit claims, the order a teacher intends, and how the whole thing fits into a term.

Three decisions shape it. A plan belongs to the course, so every section shares it and it survives from one term to the next. It is measured in instructional hours and carries no dates, because a week is not a fixed quantity and the same plan must run in autumn and spring. And units reference objectives rather than containing them, which is what makes restructuring a course safe: rearranging how you teach cannot change what you cover.

Table of Contents

  1. Introduction
  2. Motivation
  3. Specification
  4. Version 1 Scope
  5. Security Considerations
  6. Backward Compatibility
  7. References

1. Introduction

Every teacher plans a course before teaching it. They decide what the course must cover, group it into units that make sense together, put the units in an order, and work out whether it all fits in the time they have. Fitting everything into a semester is the genuinely hard part, and it is never finished — a plan is adjusted repeatedly as a term unfolds.

The platform can currently hold almost none of this. It knows about courses, sections, lessons, and terms. It has no concept of a unit, no way to record what a course intends to cover, and no way to express how long anything is expected to take.

A separate planning tool exists and can generate a plan from a standards authority, but its output is a standalone document. Nothing links it to a course, so a lesson cannot be attached to it, coverage cannot be computed from it, and no report can be produced. A teacher who spends an afternoon planning has produced a document, not a plan the platform understands.

This ARFC makes the plan part of the course. Together with ARFC-1011, which supplies the objectives, it is what allows the platform to answer what is this course meant to teach, in what order, and does it fit?

2. Motivation

Current State

Courses, sections, lessons, and terms exist. A lesson belongs to a course rather than to a class, so material is authored once and taught by every section. Sections belong to a course and to a term, and dates live on the section and on individual assignments.

Lesson ordering exists as a web of links. A lesson may be declared a prerequisite or a corequisite of another lesson in the same course, and each link is either enforced against students or advisory. This is a set of pairwise relationships rather than a numbered list, which allows a course to offer more than one valid route through its material.

A plan can be authored, and nothing can read it. The existing planning tool produces a document containing topics, goals, terms, and activities, with a timeline view. It is stored as an ordinary authored file. It is not attached to any course, and no other part of the platform consumes it.

Within that document, position is identity. A topic is identified by where it sits in the document. Reordering therefore changes which topic a given reference would point at, so nothing outside the document can safely hold a reference into it.

There is no concept of a unit, of planned time, or of coverage intent. Nothing records that a course intends to cover something, so nothing can report that it failed to.

Missing Capabilities

A course cannot state its plan. Consequently a course cannot be found to be incomplete before it is taught, only after.

Nothing can be attached to a plan. Lessons cannot be grouped into units; objectives cannot be claimed by a unit; no progress or coverage view can be organised the way a teacher thinks about their course.

Time is not modelled at all. A teacher cannot record that a unit is expected to take eighteen hours, so the platform cannot tell them their plan needs more time than the term contains — the single most useful thing it could say during planning.

A plan cannot be reused. Teaching the same course again means rebuilding the plan, and a teacher with three sections of one course has no way to plan once.

Planning ahead disturbs the present. With a single mutable document, preparing next term’s changes and running this term’s instruction are the same act.

Design Goals

  1. The plan belongs to the course. One plan, shared by every section, reusable across terms without editing.
  2. Restructuring must be safe. Rearranging units cannot change what the course covers.
  3. Time in hours, and no dates. The plan states how much time, never when.
  4. Surface the hard part. Where a plan does not fit, say so, say where, and do not quietly make the arithmetic work.
  5. Order is an intention, not a constraint. Record what the teacher plans to do without asserting it is the only valid order.
  6. Plan ahead without disturbing instruction. Preparing a future term must not alter what current sections see.
  7. Reuse by default. After the first year, reusing an existing plan should be the normal path.

3. Specification

3.1 Core Principles

Scope and sequence are separate axes. Scope is the objective set the course must cover: standards-derived, essentially flat, and stable. Sequence is units of lessons, ordered: teacher-authored, pedagogical, and frequently restructured. They change at different rates and for different reasons, and keeping them apart is what allows one to be edited without disturbing the other.

A plan belongs to the course, never to a section. This is the same architecture lessons already follow, and for the same reason: material and intent are authored once and shared by every class that teaches them.

Units reference objectives; they do not contain them. If objectives lived inside units, then merging two units or moving an objective between them would appear to change what the course covers. Referencing means restructuring is safe by construction.

Time is measured in instructional hours and carries no dates. A week is not a fixed quantity of teaching, and dates belong to the term, not the plan.

Unallocated time is entered, not inferred. Where a unit’s lessons do not fill its time, the remainder is recorded deliberately, so slack becomes something a teacher can see and defend rather than arithmetic that silently fails to add up.

Order is a default; prerequisites are the constraint. A plan records the order a teacher intends. What is legal is expressed separately, by prerequisite links, and much of a course is genuinely order-independent.

3.2 Primary Objects

Plan — a course’s scope and sequence. Carries a name, the units it contains, its total instructional hours, and its state.

Unit — a named, ordered collection of lessons covering related topics, together with the objectives it claims. The pedagogical grouping a teacher recognises.

Claim — a unit’s assertion that it is where a particular objective is taught.

Lesson placement — a lesson’s membership in a unit, with its expected duration.

Padding — deliberately unallocated instructional time, recorded within a unit or across the plan.

flowchart TB
    CO[Course] --> OBJ[Objectives<br/>the scope — flat, stable]
    CO --> PL[Plan<br/>the sequence]
    PL --> U1[Unit 1]
    PL --> U2[Unit 2]
    PL --> PAD[Plan padding]
    U1 --> L1[Lessons + unit padding]
    U2 --> L2[Lessons + unit padding]
    U1 -.->|claims| OBJ
    U2 -.->|claims| OBJ
    CO --> SE[Sections<br/>inherit the plan · carry the dates]
    style OBJ stroke-width:2px

The dotted lines are the point of the diagram. Objectives hang from the course, not from the units, and units point at them.

3.3 What a Unit Is

A unit is a collection of lessons covering related topics.

It is a pedagogical grouping, authored by a teacher, expressing that this material belongs together and is taught together. A unit on ball games might contain lessons on baseball, football, and kickball. A unit on light might contain six lessons that build on one another.

A unit is not a week, and not a lesson. It typically spans several lessons and several weeks of instruction. It is emphatically not derived from a standards authority’s hierarchy: standards are grouped in administrative ways that collectively specify a whole course’s requirements without being pedagogically ordered or grouped, and treating a standards grouping as a teaching unit produces structure no teacher recognises.

Units are named by the teacher, ordered within the plan, and freely rearranged.

3.4 Units Reference Objectives

A unit claims the objectives it is where a student will be taught. A claim is an assertion of intent: this is where we cover this.

Claims are many-to-many. An objective may be claimed by several units, because revisiting material is normal teaching — good digital citizenship may be claimed by units across a whole year, while Boolean conjunction may be claimed by exactly one. A unit normally claims several objectives.

A claim is not coverage. It states where an objective is intended to be taught. Whether work actually exists that evidences it is a separate question, answered by alignment (ARFC-1011), and the distinction between the two is what makes a plan checkable: a course whose plan claims every objective but has authored work for half of them is in a materially different condition from one that has authored everything.

Objectives survive their claims. Removing a claim, or removing the unit that made it, does not remove the objective — the objective belongs to the course. It simply becomes unclaimed, which is a reportable planning state rather than a loss.

3.5 Lessons Within a Unit

A unit contains lessons. Each placement carries the lesson’s expected duration in instructional hours.

A lesson belongs to exactly one course, permanently, which is unchanged by this ARFC. Within a course, a lesson may be placed in at most one unit — a lesson taught in two places would make both the time arithmetic and the plan’s meaning ambiguous.

Lessons within a unit need not be ordered. A unit of ball games whose lessons cover baseball, football, and kickball has no inherent order, and forcing one would misrepresent the plan. A unit may declare an intended order where one exists; where it does not, the lessons are simply the unit’s contents.

Lessons that belong to the course but sit in no unit are unplaced. This is permitted — material may be authored before it is planned — and reported, so it is visible rather than lost.

3.6 One Plan per Course

A course has at most one active plan. Two active plans would make “what does this course cover” unanswerable.

A plan may exist without a course. A teacher or curriculum lead may build a plan in advance, or keep one for a course they do not yet teach. An unbound plan is fully editable and belongs to its author’s institution; it simply governs nothing until it is bound.

Binding requires compatibility. A plan may be bound to a course only where the two concern the same subject. The platform refuses an incompatible binding rather than allowing a plan for one subject to govern a course in another.

Binding copies. When an existing plan is bound to a course, the course receives its own independent copy. The alternative — several courses sharing one plan — means a teacher editing “their” plan silently edits another course, which is a surprise in exactly the situation where surprises are most costly. Copying is what makes a plan a teacher can reason about.

3.7 Sections Inherit

Every section of a course shares the course’s plan. There is nothing to synchronise and no per-section copy: a teacher with four sections of one course plans once, and the plan is presented in each section’s context labelled as belonging to the course.

Adding a section later inherits the plan automatically. A section whose course has no plan reports that plainly rather than appearing to have an empty one.

Because there is only ever one plan, the failure mode of divergent per-section plans is structurally impossible rather than merely discouraged.

3.8 Stable Identity

A unit’s identity is independent of its name and its position. Renaming a unit, reordering the units in a plan, or moving a lesson between units does not change what a unit is, and anything referring to it continues to refer to the same unit.

This is stated explicitly because the existing planning document does not behave this way: within it, a topic’s identity is its position, so reordering changes which topic an outside reference would resolve to. That property is why nothing outside the document can safely hold a reference into it, and it is the single most important thing this ARFC changes.

The consequence a teacher experiences: rearranging a plan never detaches anything. Lessons stay in their units, units keep their claims, and links from elsewhere in the platform keep pointing where they pointed. What that guarantee protects during more disruptive edits — deletions, restructuring, changes affecting sections mid-term — is specified in ARFC-1014.

3.9 Time: Instructional Hours

A plan’s time is measured in instructional hours, not weeks or days.

A week is not a fixed quantity of teaching. Block timetables, alternating-day schedules, holidays, and short weeks all change what a week is worth, and two students in the same class may not even meet the same number of times in a given week. Planning in weeks produces a plan that is wrong for most of the timetables it will meet.

A plan declares its total instructional hours — a semester might be eighty, a full year a hundred and twenty. Each unit declares its hours, and each lesson placement its expected duration.

Hours are an expectation, not a measurement. They express what a teacher believes the material needs, which is what makes them useful during planning, before any student has done anything.

3.10 The Balance Invariant

Two sums must hold for a plan to be balanced:

Σ(lesson durations in a unit) + unit padding    = unit hours
Σ(unit hours in a plan)       + plan padding    = plan hours

Padding is deliberate, not residual. Where a unit’s lessons do not fill its hours, the teacher records the remainder as padding — for review, assessment, contingency, or the reality that a unit will overrun. Recording it makes slack visible and defensible rather than leaving arithmetic that does not add up. Padding exists at both levels, because unallocated time within a unit and unallocated time between units are different decisions.

Balance is a reported status, not a save-time gate. No one can author a plan in which every intermediate state balances, and refusing to save an unbalanced plan would make planning impossible. A plan in draft may be unbalanced for as long as its author needs. Balance is required to make a plan active — and until then the imbalance is reported, with the specific unit and the specific shortfall or excess named.

3.11 Over-Fill

Padding absorbs a plan that has time to spare. Over-fill is the opposite and more important case: the lessons need more time than exists.

Over-fill is surfaced, never absorbed. Where a unit’s lessons exceed its hours, or a plan’s units exceed its hours, the platform reports which constraint broke and by how much. It does not silently expand the unit, silently shrink a lesson, or present the arithmetic as though it worked.

The cascade is the work, not a failure of the tool. Extending a unit to fit its lessons pushes the plan over its total; absorbing that means shortening another unit, cutting material, or accepting less padding. Deciding which is a teacher’s professional judgement, and the platform’s job is to show precisely what is out of balance so the decision can be made deliberately.

3.12 No Dates

A plan contains no dates of any kind.

Dates arrive with the section — which belongs to a term — and with individual assignments. The plan says how much time material needs and in what order; it never says when.

Three things follow, and they are the practical payoff of the whole time model:

3.13 Order and Prerequisites

A plan records the order the teacher intends to teach its units. This is a default and a presentation order — it is what the teacher plans to do, not an assertion that no other order is valid.

What is legally required to precede what is expressed separately, by the prerequisite and corequisite links that already exist between lessons. Those links are a web rather than a list, and much of a course has none: an introductory physics course covering light, basic mechanics, and thermal behaviour may teach the three in any order, because they are mutually independent.

A plan is valid when its intended order respects the prerequisite links. Where a plan schedules a lesson before something it requires, that is a detectable defect rather than a matter of opinion. Where no links exist, every order validates — which is exactly the right answer for genuinely independent material.

Separating the two means a teacher may reorder freely and be warned only when they cross a real constraint, rather than being asked to justify every rearrangement or being allowed to break a genuine dependency silently.

3.14 Establishing a Plan

A plan is established in one of three ways, and the choice is the teacher’s:

Path When it fits
Generated a new course, or one whose objectives come from a standards authority
Reused from an existing plan teaching a course again, or a second course of the same subject
Built by hand full control, or a course unlike anything already planned

Generation supplies the objective set (ARFC-1011) and does not supply units. Grouping objectives and lessons into units is teacher-authored, because it is a pedagogical judgement and because standards hierarchies cannot supply it.

Provenance grants no exemption from readiness. A generated plan, a reused plan, and a hand-built plan face the same checks in §3.17. Where a plan came from does not affect whether it is complete or balanced.

3.15 Reuse, Duplication, and Renaming

Duplicating a plan produces an independent copy. Every unit, every claim, every lesson placement, and every duration is copied, the copy takes a new name, and the original is untouched. That guarantee is what makes the copy usable for experimentation: a teacher may restructure a duplicate freely without risk to the plan currently governing instruction.

A plan may be renamed at any time. A plan’s name is a label, and renaming it changes nothing else.

Reuse is the normal path after the first year. A teacher may browse the plans they have access to that are compatible with a course, and bind a copy of one. Where no compatible plan exists, that is reported plainly rather than presented as an empty list.

3.16 Plan Lifecycle and Planning Ahead

stateDiagram-v2
    [*] --> Draft: established
    Draft --> Draft: edited freely
    Draft --> Active: activated — readiness required
    Active --> Draft: superseded by a newly activated plan
    Active --> Archived: course archived
    Draft --> Archived: abandoned
    Archived --> [*]
    note right of Active
        Exactly one active plan per course.
        Sections see the active plan.
    end note

Activation is explicit and requires readiness. A plan becomes the course’s active plan by a deliberate act, not by being edited. Until then it governs nothing.

Planning ahead is duplication plus activation. A teacher preparing next term duplicates the active plan, edits the duplicate as freely as they like, and activates it when the term turns. Because sections see only the active plan, planning work cannot disturb current instruction — which is the property teachers ask for, achieved without a separate versioning concept.

What happens at the moment of activation when sections are mid-term — who is warned, what is summarised, what requires confirmation — is ARFC-1014.

3.17 Readiness

A plan is checked for readiness. Failures are reported as named defects with the specific unit or objective identified, never as a generic warning.

Completeness — every required objective is claimed by at least one unit. Optional objectives are reported as unclaimed enrichment and never block readiness.

Balance — the two sums in §3.10 hold, with no unit or plan over-filled.

Order validity — the intended order respects the prerequisite links (§3.13).

Deliverability against the target level — the checks specified in ARFC-1012 §3.16, which a plan can fail even when it is complete and balanced:

These four are the reason readiness is worth computing in August rather than discovering in May. Where a course does not use mastery grading, they do not apply.

Readiness is reported continuously, not only at activation. A teacher adjusting a plan mid-term sees immediately what their change broke.

3.18 API Surface

Method Path operationId Description
POST /v2/plans createPlanV2 Create a plan, optionally unbound
GET /v2/plans listPlansV2 Plans the caller may access, filterable by subject compatibility
GET /v2/courses/{course-eid}/plan getCoursePlanV2 A course’s active plan, with units, claims, placements, and hours
GET /v2/sections/{section-eid}/plan getSectionPlanV2 The inherited plan in a section’s context
POST /v2/courses/{course-eid}/plan bindPlanToCourseV2 Bind a copy of an existing plan to a course
POST /v2/plans/{plan-eid}/duplicate duplicatePlanV2 Produce an independent copy under a new name
PATCH /v2/plans/{plan-eid} updatePlanV2 Rename, or set total instructional hours and plan padding
POST /v2/plans/{plan-eid}/activate activatePlanV2 Make a plan the course’s active plan
POST /v2/plans/{plan-eid}/units createPlanUnitV2 Add a unit
PATCH /v2/plans/{plan-eid}/units/{unit-eid} updatePlanUnitV2 Rename, or set hours and unit padding
PUT /v2/plans/{plan-eid}/units/order reorderPlanUnitsV2 Set the intended order of units
PUT /v2/plans/{plan-eid}/units/{unit-eid}/objectives/{objective-eid} claimObjectiveForUnitV2 Claim an objective for a unit
DELETE /v2/plans/{plan-eid}/units/{unit-eid}/objectives/{objective-eid} releaseObjectiveClaimV2 Remove a claim
PUT /v2/plans/{plan-eid}/units/{unit-eid}/lessons/{lesson-eid} placeLessonInUnitV2 Place a lesson in a unit with its expected duration
DELETE /v2/plans/{plan-eid}/units/{unit-eid}/lessons/{lesson-eid} removeLessonFromUnitV2 Remove a placement, leaving the lesson unplaced
GET /v2/plans/{plan-eid}/readiness getPlanReadinessV2 All readiness defects, each naming the unit or objective concerned

Reordering accepts the intended order as a whole rather than as a series of moves, so a rearrangement either applies completely or leaves the plan unchanged. A reorder that would violate a prerequisite link is reported as a readiness defect rather than refused — the teacher may be mid-restructure.

3.19 Authorization Model

Establishing and editing a plan requires curriculum authority over the course. An institution may reserve this to a curriculum lead, in which case instructors see the plan read-only, with edit controls absent rather than present and failing.

Every read tells the caller what they may do, so a client can present a plan as editable or read-only without discovering the answer by attempting a change.

Binding a plan to a course is a heavier act than editing one, because it determines what an entire course covers. An institution may grant editing to instructors while reserving binding and activation to a curriculum lead.

Activation may be restricted independently of editing. Where instruction is under way, activating a plan changes what every section of the course is working from, which is why it is separable.

An unbound plan is visible to its author and to those they share it with, within their institution. Binding does not widen access to the original, since binding copies.

3.20 Absent and Incomplete

State Meaning Must not be shown as
No plan the course has no active plan an empty plan, or a plan with no units
Draft only a plan exists but has not been activated the course’s plan
Unclaimed objective no unit claims it an objective the course rejects
Unplaced lesson authored but in no unit a lesson that does not exist
Unbalanced the sums do not hold balanced, or silently corrected
Hours not set the author has not stated a duration zero hours

The last row matters during authoring. A unit whose hours are not yet set is not a unit of no duration, and treating it as zero would report a plan as balanced when it has simply not been filled in.

4. Version 1 Scope

Included

Excluded

5. Security Considerations

A plan is substantial professional work and may be valuable. A well-constructed plan represents an afternoon at minimum and often far more, and for an institution that has refined one over years it is a commercial asset. Plans are scoped to their author’s institution, and binding copies rather than sharing so that no course’s plan can be altered from outside it.

Activation changes what every section of a course is working from. It is separable from editing precisely so that an institution can allow a teacher to prepare a plan while reserving the decision to put it into force. Every activation records who performed it and when.

Readiness reports contain no student data. They describe a plan — which objectives are unclaimed, which units are over-filled, which requirements cannot be met. Reading readiness grants no access to student records and must not become an indirect route to them.

Editability must be stated, not discovered. A client that learns a plan is read-only by attempting an edit and being refused will have already shown the user an editable interface. Every read reports the caller’s permissions so the interface is correct before the attempt.

Unbound plans still belong to an institution. A plan governing no course is not ownerless. It carries the same access scoping as a bound one, so a draft prepared for next year is not more widely readable than the plan currently in force.

6. Backward Compatibility

Nothing existing changes. Courses, sections, lessons, terms, and the prerequisite links between lessons behave exactly as they do today. A course without a plan behaves precisely as every course behaves now.

Prerequisite links are reused, not replaced. The existing web of lesson relationships becomes the constraint that validates a plan’s intended order. Institutions that have invested in prerequisite links get order validation immediately, and those that have not are unaffected — a course with no links has every order validate.

Existing planning documents are not imported automatically. They cannot be, safely. Within those documents a topic’s identity is its position (§3.8), so nothing outside can reliably determine which topic a given reference means, and the structures they contain were produced with flattened grouping, guessed grade levels, and a discarded pacing selection (ARFC-1011 §2). Importing them wholesale would carry all of that into the permanent record. An explicit, reviewed import path may be worth building later; it is out of scope here, and until then existing documents remain readable where they are.

Unplaced lessons are the normal starting condition. Every existing course has lessons and no plan, so establishing a plan begins with every lesson unplaced. This is a reported state rather than a defect, and a partially planned course is a legitimate condition rather than a broken one.

Hours are absent for existing material and must not be defaulted. A lesson has no recorded expected duration, and treating that as zero would report a plan as balanced when nothing has been estimated. Absent hours are absent, and a plan cannot be balanced — and therefore cannot be activated — until they are stated.

7. References

Platform Documentation

Author

ĀYŌDÈ Development Team Codermerlin Academy Architecture