# ELI5 — Explain Like I Am 5
> A [Claude Code](https://claude.ai) skill that explains anything to anyone — kids, managers, engineers, parents. It adapts tone, vocabulary, analogies, and framing to match the audience.
Ever needed to explain a technical concept to your manager? Or break down code for a 5th grader? ELI5 makes Claude automatically adjust its explanation style based on who's listening.
Read the full blog post on how this skill was built: [Building an ELI5 Skill for Claude](https://andrewou.pages.dev/posts/building-an-eli5-skill-for-claude/)
## Supported Audiences
| Category | Examples |
|----------|---------|
| **Ages** | 5, 10, 15, 20, 30, 40+ |
| **Grade Levels** | 5th grade, Middle school, Senior High, College, Graduate school |
| **Job Roles** | Manager, Engineer, Designer, Director, Product Manager |
| **Relationships** | Wife, Husband, Parents, Kids, Friend |
## Usage Examples
```
ELI5 what a database index is
Explain this code to my manager
Break down how git merge conflicts work for a 5th grader
Explain this error to my mom
Simplify this for a designer
```
## How It Works
The skill detects the target audience from your prompt and calibrates:
- **Vocabulary** — no jargon for kids, proper terminology for engineers
- **Analogies** — toys and playground for age 5, business outcomes for managers
- **Tone** — playful for children, professional for directors, warm for family
- **Depth** — short and sweet for simple audiences, nuanced for grad students
- **Framing** — impact/risk for managers, UX for designers, architecture for engineers
## Installation
Copy the skill into your Claude Code skills directory:
```bash
git clone https://github.com/DreambigOu/ELI5.git
cp -r ELI5/skills/eli5 ~/.claude/skills/eli5
```
Then use it in Claude Code by saying things like "ELI5 this" or "explain this to my manager."
## Evaluations
Read the full guide on how the eval system works: [How to Evaluate a Claude Code Skill](https://andrewou.pages.dev/posts/how-to-evaluate-a-claude-code-skill/)
### Adding a New Test Case
Test cases are defined in `eli5-workspace/evals.json`. Add a new entry to the `evals` array:
```json
{
"id": 3,
"name": "explain-recursion-teenager",
"prompt": "Explain recursion like I'm 15",
"audience": "Age 15",
"assertions": [
"Uses social media, gaming, or phone references as analogies",
"Tone is casual but not cringey — no 'fellow kids' energy",
"Correctly explains the concept of a function calling itself",
"Mentions a base case or stopping condition"
]
}
```
Each test case needs:
- A **prompt** — what the user would say to Claude
- A **name** — directory-friendly identifier for storing results
- **Assertions** — specific, verifiable criteria to grade against (4 per test works well)
### Running Evaluations
**Prerequisites:** [Claude Code CLI](https://docs.anthropic.com/en/docs/claude-code) installed and the skill installed at `~/.claude/skills/eli5/`.
```bash
# Run all tests + auto-grade with pass/fail
python eli5-workspace/run-evals.py
# Run a single test
python eli5-workspace/run-evals.py --test=1
# Skip baseline, only test the skill
python eli5-workspace/run-evals.py --with-skill-only
# Grade existing outputs without re-running tests
python eli5-workspace/run-evals.py --grade-only
```
The script does three things:
1. **Runs each prompt** twice — once with the skill, once without (baseline)
2. **Auto-grades** every output against its assertions using Claude
3. **Prints a pass rate summary** comparing skill vs baseline
Example output:
```
--- Test 1: explain-db-index-age5 ---
[with skill]
PASS #1 — No technical jargon present
PASS #2 — Uses book/page analogy and toy/messy room analogy
PASS #3 — Sentences are short and conversational
PASS #4 — Warm, enthusiastic tone with "huuuge", "super duper fast"
[baseline]
PASS #1 — No technical jargon found
FAIL #2 — Uses phone book analogy, not child-friendly
PASS #3 — Sentences are generally short
FAIL #4 — Tone is informative but encyclopedic
=========================================
PASS RATE SUMMARY — Iteration 1
=========================================
With Skill: 10/12 passed (83.3%)
Without Skill: 5/12 passed (41.6%)
Delta: 41.7%
=========================================
```
Results are saved to `eli5-workspace/iteration-N/`, auto-incrementing with each run. Each test case produces `grading.txt` files with detailed evidence.
### Current Results
See [eli5-workspace/eval-results.md](eli5-workspace/eval-results.md) for the full evaluation strategy and detailed grading.
| Metric | With Skill | Without Skill | Delta |
|--------|-----------|---------------|-------|
| Pass Rate | **83.3%** | 41.6% | +41.7% |
The biggest improvement is in audience-specific framing — especially for non-technical audiences like managers (0% baseline to 50% with skill).
## Contributing
PRs welcome! Ideas for improvement:
- Add more audience types (e.g., CEO, intern, journalist)
- Add non-English language support
- Improve evaluation coverage with more test cases
## License
MIT