batdetect2/docs/source/how_to/tune-detection-threshold.md

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# How to tune detection threshold
Use this guide to compare detection outputs at different threshold values.
The goal is not to find a universal threshold.
The goal is to choose a threshold that fits your reviewed local data and the project trade-off between missed calls and false positives.
## 1) Start with a baseline run
Run an initial prediction workflow and keep outputs in a dedicated folder.
## 2) Sweep threshold values
Run `predict` multiple times with different thresholds (for example `0.1`,
`0.3`, `0.5`) and compare output counts and quality on the same validation
subset.
```bash
batdetect2 predict directory \
path/to/model.ckpt \
path/to/audio_dir \
path/to/outputs_thr_03 \
--detection-threshold 0.3
```
Keep each threshold run in a separate output directory.
That makes it easier to compare counts and inspect example files without mixing results.
## 3) Validate against known calls
Use files with trusted annotations or expert review to select a threshold that
fits your project goals.
Check both:
- obvious false positives,
- obvious missed calls.
If class interpretation matters downstream, inspect class ranking behavior as well, not just detection counts.
## 4) Record your chosen setting
Write down the chosen threshold and rationale so analyses are reproducible.
For conceptual trade-offs, see
{doc}`../explanation/model-output-and-validation`.