THE RESULT
What the data shows
The largest computed metric is 2.35 for External / Median baseline; the smallest is 1.55 for Full / Extra trees. Metric: mae (Ring-count MAE).
External measurements are chosen by measurement availability; field robustness is not established.
| model | mae | rmse | r2 | bias | measurements | variant |
|---|---|---|---|---|---|---|
| Median baseline | 2.35 | 3.424 | -0.09594 | -1.013 | External | External / Median baseline |
| Ridge | 1.834 | 2.677 | 0.3302 | -0.08277 | External | External / Ridge |
| Extra trees | 1.808 | 2.629 | 0.3538 | -0.04554 | External | External / Extra trees |
| Median baseline | 2.35 | 3.424 | -0.09594 | -1.013 | Full | Full / Median baseline |
| Ridge | 1.634 | 2.316 | 0.4985 | -0.008641 | Full | Full / Ridge |
| Extra trees | 1.55 | 2.247 | 0.5283 | -0.04281 | Full | Full / Extra trees |
THE METHOD
From source to answer
Paired ablation of external-only versus full measurements with common input-group splits.
The Python source exposes this study’s transformations. The complete project download includes shared preparation and evaluation routines.
EVALUATION
How the result was checked
Fixed 80/20 split of unique input groups (seed 42); exact input duplicates stay together.
Fixed configurations specified before scoring; no tuning on the holdout.
Target and input features
Target: rings
Inputs: sex, length, diameter, height, whole_weight, shucked_weight, viscera_weight, shell_weight
THE NEXT DECISION
What follows from the finding
Compare measurement effort and external accuracy before proposing a field workflow.
Where the conclusion stops
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 reuse observations or holdouts. These are historical analyses; associations and backtests do not demonstrate commercial impact. Further model tuning needs new, untouched evaluation data.