# 097. Abalone ring-count estimation

**Question:** Can physical measurements estimate observed ring counts beyond a median baseline?

## Result

The largest computed metric is 2.35 for Median baseline; the smallest is 1.55 for Extra trees. Metric: mae (Ring-count MAE).

The target is ring count. Some predictors require dissection, so this full-feature model is not a non-destructive measurement protocol.

![Abalone ring-count estimation](outputs/chart.png)

| model | mae | rmse | r2 | bias |
| --- | --- | --- | --- | --- |
| Median baseline | 2.35 | 3.424 | -0.09594 | -1.013 |
| Ridge | 1.634 | 2.316 | 0.4985 | -0.008641 |
| Extra trees | 1.55 | 2.247 | 0.5283 | -0.04281 |

The chart shows 3 of 3 result rows; the table previews the first 3 in the analysis-defined order. [Download the full result table](outputs/results.csv). Numerical values are computed from the source; missing results stay unavailable.

## Method

Grouped-input regression with original ring-count errors.

The study uses shared source preparation and reusable statistical routines. Its specific transformations are in [analysis.py](analysis.py), and common model/evaluation code is in [portfolio/methods.py](../../portfolio/methods.py). The [notebook](analysis.ipynb) executes the study and displays the saved results.

## Evaluation

Fixed 80/20 split of unique input groups (seed 42); exact input duplicates stay together. Training observations: 3,341; test observations: 836. Fixed configurations specified before scoring; no tuning on the holdout.

Target: `rings`. Features: sex, length, diameter, height, whole_weight, shucked_weight, viscera_weight, shell_weight. Model results and row membership are recorded in [evaluation.json](outputs/evaluation.json).

## Decision and limitations

Evaluate with independently collected animals and sampling sites before biological use.

Physical measurements use source scaling. Rings are the modeled target; the source describes an approximate age conversion. Site and animal group identifiers are unavailable, limiting biological generalization. 

Related studies may share observations or holdouts. These are focused analytical studies, not independent replications or deployed business systems. Any model refinements informed by these results need new untouched evaluation data. No commercial impact is inferred from an association or backtest.

## Reproduce

From the repository root, after installing `requirements.txt`:

```powershell
python projects/097-abalone-ring-count-estimation/analysis.py
```

Source data are downloaded automatically if absent. Original archives are retained unchanged and checked by SHA-256. The cleaned cache normalizes column names; field-specific changes are visible in [data preparation](../../portfolio/data.py). Runtime evidence is in [receipt.json](outputs/receipt.json).

## Source

[Abalone](https://archive.ics.uci.edu/dataset/1/abalone), Nash et al. (1994). [CC BY 4.0](https://creativecommons.org/licenses/by/4.0/). Source data are transformed and aggregated in this study. [Source provenance](../../data/provenance/abalone.json) and [prepared-data audit](../../data/provenance/abalone_prepared.json) record the downloaded files, field coverage and hashes.