Skip to content

Slot: Extraction Method (extraction_method)

How a gridded value was extracted at the patient's coordinates. Default for DeGAUSS daymet / narr is inverse_distance_weighted_4_nearest_cells.

Tier: core

Why this slot matters

This is the single biggest lever in turning a grid into a per-person value: different extraction methods yield different exposure values at the very same point. If the method is unknown, exposure values are not reproducible and cannot be compared across studies or tool runs.

In plain terms

A patient's home almost never sits exactly at the centre of a data tile, so a rule is needed to pick or blend nearby tile values into one number for that spot — take the closest tile, average the four nearest ones, and so on. This field records which rule was used.

URI: envar:slot/extraction_method

Applicable Classes

Name Description Modifies Slot
SpatialReference Spatial provenance of an environmental exposure value: the native grid / foot... yes

Properties

Type and Range

Property Value
Range ExtractionMethodEnum
Domain Of SpatialReference

Cardinality and Requirements

Property Value

Examples

Value
inverse_distance_weighted_4_nearest_cells
area_weighted_polygon_mean

See Also

Identifier and Mapping Information

Annotations

property value
tier core
justification This is the single biggest lever in turning a grid into a per-person value: different extraction methods yield different exposure values at the very same point. If the method is unknown, exposure values are not reproducible and cannot be compared across studies or tool runs.
explanation A patient's home almost never sits exactly at the centre of a data tile, so a rule is needed to pick or blend nearby tile values into one number for that spot — take the closest tile, average the four nearest ones, and so on. This field records which rule was used.
covered_by None

Schema Source

Mappings

Mapping Type Mapped Value
self envar:extraction_method
native envar:extraction_method

LinkML Source

name: extraction_method
annotations:
  tier:
    tag: tier
    value: core
  justification:
    tag: justification
    value: 'This is the single biggest lever in turning a grid into a per-person value:
      different extraction methods yield different exposure values at the very same
      point. If the method is unknown, exposure values are not reproducible and cannot
      be compared across studies or tool runs.'
  explanation:
    tag: explanation
    value: A patient's home almost never sits exactly at the centre of a data tile,
      so a rule is needed to pick or blend nearby tile values into one number for
      that spot — take the closest tile, average the four nearest ones, and so on.
      This field records which rule was used.
  covered_by:
    tag: covered_by
    annotations:
      omop_gaia:
        tag: omop_gaia
        annotations:
          extent:
            tag: extent
            value: absent
          status:
            tag: status
            value: asserted
          where:
            tag: where
            value: no column
          note:
            tag: note
            value: No extraction-method slot in gaiaCatalog or gaia-db; only the implicit
              st_within join semantics of working.spatial_join_exposure exist, undocumented.
      degauss:
        tag: degauss
        annotations:
          extent:
            tag: extent
            value: absent
          status:
            tag: status
            value: asserted
          where:
            tag: where
            value: no column
          note:
            tag: note
            value: DeGAUSS applies IDW-4-nearest by default but records no extraction-method
              field.
      amadeus:
        tag: amadeus
        annotations:
          extent:
            tag: extent
            value: absent
          status:
            tag: status
            value: asserted
          where:
            tag: where
            value: no column
          note:
            tag: note
            value: Amadeus emits no extraction-method field.
      cher:
        tag: cher
        annotations:
          extent:
            tag: extent
            value: absent
          status:
            tag: status
            value: asserted
          where:
            tag: where
            value: no column
          note:
            tag: note
            value: C-HER's data-level codes track processing stage, not the point-to-cell
              extraction rule; no extraction-method field.
      codata:
        tag: codata
        annotations:
          extent:
            tag: extent
            value: out_of_layer
          status:
            tag: status
            value: asserted
          where:
            tag: where
            value: no column
          note:
            tag: note
            value: How a value was extracted from a grid is instance-layer provenance
              the conceptual EV/DDI-CDI layer deliberately omits.
description: How a gridded value was extracted at the patient's coordinates. Default
  for DeGAUSS daymet / narr is `inverse_distance_weighted_4_nearest_cells`.
title: Extraction Method
examples:
- value: inverse_distance_weighted_4_nearest_cells
  description: DeGAUSS default for point extraction (Daymet Tmax scenario)
- value: area_weighted_polygon_mean
  description: polygon aggregation (ACAG PM2.5 tract scenario)
from_schema: https://w3id.org/linkml/microschemas/envar
see_also:
- https://degauss.org/
rank: 1000
domain_of:
- SpatialReference
range: ExtractionMethodEnum