interleaving-unit-planner

name	interleaving-unit-planner
description	Redesign a blocked topic sequence into an interleaved plan with mixed practice across related topics. Use when planning units, homework schedules, or revision programmes.
disable-model-invocation	false
user-invocable	true
effort	medium
skill_id	interleaving-unit-planner
skill_name	Interleaving Unit Planner
domain	memory-learning-science
version	1.0
evidence_strength	strong
evidence_sources	["Kornell & Bjork (2008) — Learning concepts and categories: is spacing the enemy of induction?","Rohrer et al. (2015) — Interleaved practice improves mathematics learning in a classroom setting","Taylor & Rohrer (2010) — The effects of interleaved practice on learning","Bjork & Bjork (2011) — Making things hard on yourself, but in a good way: creating desirable difficulties","Pan (2015) — The interleaving effect: mixing it up boosts learning"]
input_schema	{"required":[{"field":"topics","type":"array","description":"The sequence of topics currently planned in blocked order"},{"field":"subject","type":"string","description":"The subject area and year group"},{"field":"unit_length","type":"string","description":"How many lessons or weeks the unit covers"}],"optional":[{"field":"prerequisite_dependencies","type":"array","description":"Topics that must be taught before others (hard constraints)"},{"field":"curriculum_sequence","type":"string","description":"From context engine: mandated curriculum order"},{"field":"student_profiles","type":"array","description":"From context engine: class ability profile, prior knowledge levels"}]}
output_schema	{"type":"object","fields":[{"field":"interleaved_sequence","type":"array","description":"Restructured lesson sequence with interleaving applied"},{"field":"interleaving_rationale","type":"string","description":"Why these specific topics benefit from interleaving"},{"field":"teacher_briefing","type":"string","description":"How to explain the approach to students who will find it harder"},{"field":"blocked_vs_interleaved","type":"string","description":"Side-by-side comparison of original and interleaved sequence"}]}
chains_well_with	["spaced-practice-scheduler","retrieval-practice-generator","practice-problem-sequence-designer","cognitive-load-analyser"]
teacher_time	5 minutes
tags	["interleaving","desirable-difficulty","planning","memory","practice"]

Interleaving Unit Planner

What This Skill Does

Takes a blocked topic sequence (Topic A, A, A, then Topic B, B, B) and restructures it to interleave related but distinct concepts (A, B, A, C, B, A...), producing a sequence that exploits the interleaving effect to improve long-term retention and discrimination between similar concepts. The output includes the restructured plan, the rationale for interleaving these specific topics, and a briefing for explaining the approach to students. AI is specifically valuable here because interleaving requires identifying which topics benefit from interleaving (related but distinct concepts), which must stay blocked (genuinely prerequisite knowledge), and how to sequence the interleaving pattern — a task that requires understanding both the cognitive science and the specific subject content.

Evidence Foundation

Kornell & Bjork (2008) demonstrated that interleaving the study of different categories (as opposed to studying each category in a block) improved later classification accuracy by 30–40%, despite students rating blocked study as more effective. Rohrer et al. (2015) confirmed these findings in a real mathematics classroom: students who practised interleaved problem sets scored 25% higher on a delayed test than students who practised blocked problem sets. Taylor & Rohrer (2010) showed that the benefit of interleaving is especially strong for tasks requiring discrimination — knowing which strategy or concept to apply, not just how to apply it. Bjork & Bjork (2011) explain interleaving as a "desirable difficulty" — it makes initial learning feel harder and slower, but produces substantially better long-term retention and transfer. Critically, interleaving works because it forces learners to discriminate between similar concepts on every practice attempt, rather than knowing the answer type in advance because they're in a "block" of that topic.

Input Schema

The teacher must provide:

• Topics: The current sequence of topics, in the order currently planned. e.g. ["Fractions — addition", "Fractions — subtraction", "Fractions — multiplication", "Fractions — division"]
• Subject: Subject area and year group. e.g. "Year 8 Mathematics"
• Unit length: Duration of the unit. e.g. "12 lessons over 4 weeks"

Optional (injected by context engine if available):

• Prerequisite dependencies: Topics that must come before others. e.g. "Addition must precede subtraction"
• Curriculum sequence: Any mandated order from the school's scheme of work
• Student profiles: Class ability profile and prior knowledge data

Prompt

You are an expert in the cognitive psychology of learning, specialising in the interleaving effect and desirable difficulties. You have deep knowledge of Kornell & Bjork (2008), Rohrer et al. (2015), and Taylor & Rohrer (2010) on how interleaved practice improves discrimination and long-term retention compared to blocked practice.

Your task is to restructure the following blocked topic sequence into an interleaved plan:

**Subject:** {{subject}}
**Current blocked sequence:** {{topics}}
**Unit length:** {{unit_length}}

The following optional context may or may not be provided. Use whatever is available; ignore any fields marked "not provided."

**Prerequisite constraints:** {{prerequisite_dependencies}} — if provided, these are hard constraints: do not interleave a topic before its prerequisite has been taught. If not provided, infer likely prerequisites from the topic content and flag your assumptions.
**Mandated sequence:** {{curriculum_sequence}} — if provided, respect this where possible and explain any deviations. If not provided, treat the listed topic order as the teacher's preferred sequence.
**Student profiles:** {{student_profiles}} — if provided, adjust the density of interleaving based on ability (lower-ability students may need more initial blocked practice before interleaving begins). If not provided, design for a typical mixed-ability class.

Apply these evidence-based principles:

1. **Interleave related but distinct concepts.** Interleaving works best when topics are related enough to require discrimination but distinct enough to have different solution strategies. Topics that are entirely unrelated (e.g., fractions and Shakespeare) don't benefit — there's no discrimination challenge. Topics that are almost identical (e.g., two lessons on the same sub-skill) should stay blocked during initial instruction.

2. **Teach before interleaving.** Each topic needs initial instruction in a focused block (typically 1–2 lessons) before it enters the interleaved rotation. Interleaving is a practice strategy, not an instruction strategy. Students need to understand each concept individually before being asked to discriminate between them.

3. **Introduce interleaving progressively.** Start with 2-topic interleaving, then add topics as students become comfortable. Don't interleave all topics simultaneously from lesson 1.

4. **Expect it to feel harder.** Kornell & Bjork (2008) found that students rated blocked practice as more effective even when interleaved practice produced better outcomes. Build in a brief explanation for students about why this approach feels harder but works better.

5. **Respect prerequisite dependencies.** Some topics genuinely require prior knowledge of another topic. These must stay in sequence. Interleave around constraints, not through them.

6. **Include discrimination practice.** The key benefit of interleaving is forcing students to decide WHICH strategy or concept applies, not just HOW to apply it. Include mixed-practice tasks where students must first identify the problem type.

Return your output in this exact format:

## Interleaved Unit Plan: [Subject/Unit Title]

### Original Blocked Sequence vs. Interleaved Sequence

A side-by-side comparison showing the original plan and the restructured plan.

### Interleaved Lesson Sequence

For each lesson, show:
- **Lesson [N]:** [Primary teaching focus] + [Interleaved practice from previous topic(s)]
- Note which topics are being interleaved in practice tasks

### Interleaving Rationale

3–4 sentences explaining why these specific topics benefit from interleaving, what discrimination challenge it creates, and what the expected benefit is.

### Student Briefing Script

A 4–5 sentence script the teacher can use to explain to students why the practice feels harder and why that's productive.

### Practice Task Examples

For 2–3 lessons, provide specific interleaved practice tasks that force discrimination between topics.

**Self-check before returning output:** Verify that (a) prerequisite dependencies are respected, (b) each topic receives initial blocked instruction before entering interleaved practice, (c) the interleaving is between related concepts that require discrimination, (d) mixed practice tasks require students to identify the problem type, not just solve it, and (e) the plan is realistic for the given number of lessons.