---
name: risk-distribution-fitter-dbd3987480c5
description: Probability distribution fitting skill for calibrating uncertainty models from historical data or expert judgment
allowed-tools:
  - Read
  - Write
  - Glob
  - Grep
  - Bash
metadata:
  specialization: decision-intelligence
  domain: business
  category: simulation
  priority: medium
  tools-libraries:
    - scipy.stats
    - fitter
    - pomegranate
    - distfit
graph:
  domains: [domain:business-intelligence]
  skillAreas: [skill-area:quantitative-modeling, skill-area:statistical-analysis, skill-area:financial-risk-modeling]
  roles: [role:quantitative-analyst, role:risk-analyst, role:data-scientist]
---

# Risk Distribution Fitter

## Overview

The Risk Distribution Fitter skill provides capabilities for calibrating probability distributions from historical data or expert judgment. It supports both data-driven fitting using statistical methods and expert elicitation protocols for subjective probability assessment.

## Capabilities

- Maximum likelihood estimation (MLE)
- Method of moments estimation
- Bayesian parameter estimation
- Goodness-of-fit testing (KS, AD, Chi-square)
- Distribution comparison and selection
- Expert elicitation protocol support (3-point, 5-point)
- PERT distribution calculation
- Visualization of fitted distributions

## Used By Processes

- Monte Carlo Simulation for Decision Support
- Predictive Analytics Implementation
- Decision Quality Assessment

## Usage

### Data-Driven Fitting

```python
# Fit distributions to historical data
fitting_config = {
    "data": [/* historical observations */],
    "candidate_distributions": [
        "normal", "lognormal", "gamma", "weibull",
        "exponential", "beta", "triangular"
    ],
    "fitting_method": "mle",
    "selection_criterion": "AIC"
}
```

### Expert Elicitation

```python
# 3-point estimate (PERT)
expert_estimate = {
    "method": "PERT",
    "minimum": 50000,
    "most_likely": 75000,
    "maximum": 120000,
    "confidence_level": 0.90  # optional: confidence that true value is within range
}

# 5-point estimate (for more precision)
detailed_estimate = {
    "method": "5_point",
    "P10": 45000,
    "P25": 60000,
    "P50": 75000,
    "P75": 95000,
    "P90": 115000
}
```

### Supported Distributions

| Distribution | Use Case | Parameters |
|-------------|----------|------------|
| Normal | Symmetric, unbounded | mean, std |
| Lognormal | Right-skewed, positive | mu, sigma |
| Triangular | Bounded with mode | min, mode, max |
| PERT | Bounded, weighted mode | min, mode, max |
| Uniform | Equal probability | min, max |
| Beta | Bounded, flexible shape | alpha, beta |
| Gamma | Positive, right-skewed | shape, scale |
| Weibull | Reliability/time | shape, scale |
| Exponential | Memoryless | rate |

### Goodness-of-Fit Tests

- **Kolmogorov-Smirnov (KS)**: Distribution-free, sensitive to center
- **Anderson-Darling (AD)**: More sensitive to tails
- **Chi-Square**: Categorical/binned data
- **Cramér-von Mises**: Similar to KS, different weighting

### Model Selection Criteria

- **AIC (Akaike Information Criterion)**: Balance fit and complexity
- **BIC (Bayesian Information Criterion)**: Stronger penalty for parameters
- **Log-Likelihood**: Raw fit quality

## Input Schema

```json
{
  "fitting_mode": "data_driven|expert_elicitation",
  "data_driven_config": {
    "data": ["number"],
    "candidate_distributions": ["string"],
    "fitting_method": "mle|mom|bayesian",
    "selection_criterion": "AIC|BIC|likelihood"
  },
  "expert_elicitation_config": {
    "method": "3_point|5_point|PERT|direct",
    "estimates": "object",
    "confidence_level": "number"
  },
  "options": {
    "gof_tests": ["KS", "AD", "chi_square"],
    "visualize": "boolean",
    "compare_all": "boolean"
  }
}
```

## Output Schema

```json
{
  "best_fit": {
    "distribution": "string",
    "parameters": "object",
    "gof_statistics": {
      "test_name": {
        "statistic": "number",
        "p_value": "number"
      }
    },
    "selection_score": "number"
  },
  "all_fits": [
    {
      "distribution": "string",
      "parameters": "object",
      "scores": "object"
    }
  ],
  "summary": {
    "mean": "number",
    "std": "number",
    "percentiles": "object"
  },
  "visualization_path": "string",
  "recommendations": ["string"]
}
```

## Best Practices

1. Use data-driven fitting when sufficient historical data exists (n > 30)
2. Validate fitted distributions against holdout data
3. Use PERT for expert estimates when asymmetry is expected
4. Document expert credentials and elicitation process
5. Consider mixture distributions for multimodal data
6. Always visualize fitted distribution against data/estimates
7. Use multiple goodness-of-fit tests for robustness

## Expert Elicitation Guidelines

1. Explain probability concepts clearly
2. Use familiar reference points
3. Ask for extreme estimates first, then middle
4. Check for overconfidence (typical: too narrow ranges)
5. Consider debiasing techniques
6. Document reasoning behind estimates

## Integration Points

- Feeds into Monte Carlo Engine for simulation inputs
- Supports Calibration Trainer for expert accuracy assessment
- Connects with Bayesian Network Analyzer for CPT estimation
- Integrates with Risk Register Manager for risk quantification


---
Source attribution: a5c-ai
Original project: https://github.com/a5c-ai/babysitter
License: MIT
License information: https://opensource.org/license/mit
Original upstream instructions; downloaded from Mega AI Hub.

## Upstream license notice

MIT License

Copyright (c) 2026 Gabriel Moreira

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.



# Mega AI Hub resource metadata

Creator / publisher: a5c-ai
Original project: https://github.com/a5c-ai/babysitter
Attribution basis: Upstream repository explicitly recorded in package mirror path

Fields of work: Data & Analytics, Marketing, Product Management, Sales
Roles: Business Development, Data Analyst, Growth Marketer, Marketing Analyst, Product Manager
Specialties: API
Tools: Distfit, Fitter, Pomegranate, Scipy.Stats
Country applicability: Country not specified
Classification basis: Source catalog labels
Instruction SHA-256: 1b3e52593d5b4fcc8fd993ace9a9ffbe5f7c44f1e51081b78a2cc049ce022160
