Tier 1

mece_validation

Validate that a list is MECE (Mutually Exclusive, Collectively Exhaustive). Identifies overlaps and gaps.

Usage in Claude Code: /mece_validation your question here

MECE Validation

Input: $ARGUMENTS


Purpose

Validate that a list achieves MECE quality:

  • Mutually Exclusive (ME): No item belongs to multiple categories
  • Collectively Exhaustive (CE): All possible items are covered

This skill identifies overlaps (ME violations) and gaps (CE violations).


MECE Spectrum

Perfect MECE is often impossible. This skill uses a soft MECE approach:

LevelME (Overlaps)CE (Gaps)When Acceptable
Perfect MECE0 overlaps0 gapsFormal specifications
Soft MECE< 5% overlap< 10% gapsMost business use
Good Enough< 15% overlap< 20% gapsBrainstorming, early drafts
Needs Work> 15% overlap> 20% gapsRequires revision

The Validation Process

Step 1: Confirm Structure

Identify what you’re validating:

VALIDATING: [list name/description]

STRUCTURE:
- Total items: [N]
- Categories: [list of categories if hierarchical]
- Dimensions covered: [if from space_enumeration]
- Target MECE level: [Perfect / Soft / Good Enough]

Step 2: Check Mutual Exclusivity (ME)

For each item, check: Does it fit in multiple categories?

MUTUAL EXCLUSIVITY CHECK:

| Item | Primary Category | Also Fits? | Overlap? |
|------|------------------|------------|----------|
| [Item 1] | [Cat A] | No | [x] ME |
| [Item 2] | [Cat B] | [Cat C] | [!] OVERLAP |
| [Item 3] | [Cat A] | No | [x] ME |
...

OVERLAPS FOUND: [N]
OVERLAP RATE: [N / Total] = [X%]

For each overlap, decide:

  1. Assign to primary: Pick one category, note secondary
  2. Split the item: Create more specific sub-items
  3. Merge categories: If overlap is systematic
  4. Accept overlap: If categories are perspectives, not buckets

Step 3: Check Collective Exhaustiveness (CE)

3A: Dimension Coverage Check

If dimensions are known (from /dimension_discovery):

DIMENSION COVERAGE:

| Dimension | Values | Items Found | Missing? |
|-----------|--------|-------------|----------|
| [Dim 1] | [v1, v2, v3] | [3, 2, 4] | No |
| [Dim 2] | [v1, v2] | [5, 0] | YES: v2 |
...

GAPS FOUND: [N]
GAP RATE: [Missing combinations / Total possible] = [X%]

3B: Edge Case Check

Check for items that might be missing:

EDGE CASE PROBES:

| Probe | Found in List? | If No, Add? |
|-------|----------------|-------------|
| Extreme cases (max/min) | [Y/N] | [action] |
| Boundary cases | [Y/N] | [action] |
| Negative cases (what it's NOT) | [Y/N] | [action] |
| Historical cases (past examples) | [Y/N] | [action] |
| Future cases (emerging trends) | [Y/N] | [action] |
| Edge stakeholders | [Y/N] | [action] |

3C: “What’s Missing?” Brainstorm

Ask explicitly: What could be on this list but isn’t?

WHAT'S MISSING BRAINSTORM:

Domain expert would add:
- [potential missing item 1]
- [potential missing item 2]

Contrarian would add:
- [unconventional item that belongs]

Adjacent domain has:
- [item from related field that applies]

Step 4: Calculate MECE Score

MECE SCORE:

Mutual Exclusivity:
- Overlaps: [N] / [Total] = [X%]
- ME Score: [100 - X]%

Collective Exhaustiveness:
- Gaps identified: [N]
- Estimated coverage: [Y%]
- CE Score: [Y]%

OVERALL MECE: (ME Score + CE Score) / 2 = [Z%]

ASSESSMENT:
- [ ] Perfect MECE (>95%)
- [x] Soft MECE (80-95%)
- [ ] Good Enough (60-80%)
- [ ] Needs Work (<60%)

Step 5: Generate Recommendations

Based on findings:

MECE VALIDATION RESULTS: [list name]

STATUS: [Perfect MECE / Soft MECE / Good Enough / Needs Work]

OVERLAPS TO RESOLVE:
1. [Item X] overlaps [Cat A] and [Cat B]
   -> Recommendation: [assign/split/merge/accept]

GAPS TO FILL:
1. [Dimension Y, Value Z] has no items
   -> Recommendation: [add specific items]

2. [Edge case] not covered
   -> Recommendation: [add item]

ACTIONS:
- [ ] [Specific action 1]
- [ ] [Specific action 2]

Example: Validating “Types of Machine Learning”

Input List

  1. Supervised Learning
  2. Unsupervised Learning
  3. Reinforcement Learning
  4. Deep Learning
  5. Neural Networks
  6. Semi-supervised Learning

Step 1: Structure

  • Total items: 6
  • Target: Soft MECE

Step 2: ME Check

ItemPrimaryAlso Fits?Overlap?
SupervisedLearning paradigmNo[x]
UnsupervisedLearning paradigmNo[x]
ReinforcementLearning paradigmNo[x]
Deep LearningArchitectureLearning paradigm[!] OVERLAP
Neural NetworksArchitectureDeep Learning[!] OVERLAP
Semi-supervisedLearning paradigmNo[x]

Overlaps: 2 (Deep Learning, Neural Networks) Analysis: List mixes two dimensions - paradigm and architecture

Step 3: CE Check

Dimension coverage:

  • Paradigms: Supervised, Unsupervised, Reinforcement, Semi-supervised [x]
  • Missing: Self-supervised learning

Edge cases:

  • Transfer learning? Not covered
  • Online learning? Not covered

Step 4: Score

  • ME: 4/6 clean = 67%
  • CE: Missing ~3 items from ~10 possible = 70%
  • Overall: 68% = Good Enough (Needs Work)

Step 5: Recommendations

STATUS: Good Enough - Needs Work

OVERLAPS TO RESOLVE:
1. "Deep Learning" and "Neural Networks" are architecture, not paradigm
   -> Split list into: A) Learning Paradigms, B) Architectures
   OR -> Remove Deep Learning/Neural Networks (different dimension)

GAPS TO FILL:
1. Self-supervised learning (emerging paradigm)
2. Transfer learning (important paradigm)
3. Online/incremental learning (paradigm)

RECOMMENDED REVISED LIST:
Learning Paradigms:
- Supervised
- Unsupervised
- Semi-supervised
- Self-supervised
- Reinforcement
- Transfer learning
- Online learning

Quick MECE Check (Abbreviated)

For fast validation:

QUICK MECE: [list name]

[ ] Any item fits 2+ categories? -> If yes, overlap issue
[ ] Any obvious gaps? -> If yes, CE issue
[ ] Would domain expert add anything? -> If yes, gap
[ ] Would domain expert remove anything? -> If yes, scope issue

QUICK VERDICT: [MECE / Mostly MECE / Needs Work]

Quality Checklist

Before completing:

  • Structure confirmed
  • All items checked for overlaps
  • Dimension coverage verified
  • Edge cases probed
  • “What’s missing” brainstormed
  • MECE score calculated
  • Specific recommendations provided

Integration

Use with:

  • /dimension_discovery -> Identify dimensions first
  • /space_enumeration -> Generate the list
  • /mece_validation -> Validate the list (this skill)