Data method
OpenDeco preserves what a source actually contains, records every transformation and separates source facts from normalized or derived fields.
Source acquisition
Every source begins with an acquisition record: where it came from, when it was obtained, what access terms apply, who owns the source material and whether redistribution is permitted. A citation alone is not enough to describe how OpenDeco obtained data used in an analysis.
Immutable originals
Original files are hashed and preserved in protected raw storage when rights permit. Normalization never overwrites the source object. A corrected source becomes a new acquisition and its relationship to the previous version is recorded.
Canonical exposure schema
Heterogeneous source formats are converted into a consistent exposure representation for analysis. Original identifiers and transformation lineage remain attached so each normalized field can be traced back to its source.
Units and pressure reference
Pressure, depth, altitude, time and gas values use canonical units with explicit reference conventions. Conversion is mechanical and recorded. Values are not treated as equivalent until their reference and units are known.
Missing data
Missing values remain missing unless a documented derivation is scientifically justified. Profile resolution, gas switches and outcome timing are not inferred simply to satisfy a downstream model interface.
Outcome labels
Exposure-only records, self-reported symptoms, medically assessed outcomes, experimental outcomes and VGE or Doppler observations remain distinct. They are not collapsed into a single outcome flag.
Licensing and access
A dataset can be scientifically useful even when its raw records cannot be republished. Metadata visibility, research access and public redistribution rights are recorded separately.
Quality control and release
Normalized datasets pass schema, unit, range, duplication and provenance checks before they can be frozen for a research release. Corrections create new versions. Released inputs do not change silently.