Skip to main content

​
Definition

The quasi-constant feature count test allows you to specify a threshold on the number of features that are near-constant (low variance).

​
Taxonomy

  • Task types: Tabular classification, tabular regression.
  • Availability: and .

​
Why it matters

  • Quasi-constant features have very low variance and tend to not be as useful for models.
  • If a feature shouldn’t be quasi-constant but is, you might want to re-normalize it.

​
Test configuration examples

If you are writing a tests.json, here are a few valid configurations for the character length test: 
[
  {
    "name": "No quasi-constant features",
    "description": "Asserts that there are no quasi-constant features (i.e., with a very low variance)",
    "type": "integrity",
    "subtype": "quasiConstantFeatureCount",
    "thresholds": [
      {
        "insightName": "quasiConstantFeatures",
        "measurement": "quasiConstantFeatureCount",
        "operator": "<=",
        "value": 0
      }
    ],
    "subpopulationFilters": null,
    "mode": "development",
    "usesValidationDataset": true,
    "usesTrainingDataset": false,
    "usesMlModel": false,
    "syncId": "b4dee7dc-4f15-48ca-a282-63e2c04e0689"
  }
]

[
  {
    "name": "No quasi-constant features",
    "description": "Asserts that there are no quasi-constant features (i.e., with a very low variance)",
    "type": "integrity",
    "subtype": "quasiConstantFeatureCount",
    "thresholds": [
      {
        "insightName": "quasiConstantFeatures",
        "measurement": "quasiConstantFeatureCount",
        "operator": "<=",
        "value": 0
      }
    ],
    "subpopulationFilters": null,
    "mode": "monitoring",
    "usesProductionData": true,
    "evaluationWindow": 3600,
    "delayWindow": 0,
    "syncId": "b4dee7dc-4f15-48ca-a282-63e2c04e0689"
  }
]