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:
| Level | ME (Overlaps) | CE (Gaps) | When Acceptable |
|---|---|---|---|
| Perfect MECE | 0 overlaps | 0 gaps | Formal specifications |
| Soft MECE | < 5% overlap | < 10% gaps | Most business use |
| Good Enough | < 15% overlap | < 20% gaps | Brainstorming, early drafts |
| Needs Work | > 15% overlap | > 20% gaps | Requires 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:
- Assign to primary: Pick one category, note secondary
- Split the item: Create more specific sub-items
- Merge categories: If overlap is systematic
- 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
- Supervised Learning
- Unsupervised Learning
- Reinforcement Learning
- Deep Learning
- Neural Networks
- Semi-supervised Learning
Step 1: Structure
- Total items: 6
- Target: Soft MECE
Step 2: ME Check
| Item | Primary | Also Fits? | Overlap? |
|---|---|---|---|
| Supervised | Learning paradigm | No | [x] |
| Unsupervised | Learning paradigm | No | [x] |
| Reinforcement | Learning paradigm | No | [x] |
| Deep Learning | Architecture | Learning paradigm | [!] OVERLAP |
| Neural Networks | Architecture | Deep Learning | [!] OVERLAP |
| Semi-supervised | Learning paradigm | No | [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)