Match Level & Search Confidence

Reference

Naurt provides you with three tools to understand the quality of a match from the geocoder.

1. Data Accuracy: the expected quality of geographic data for that address
2. Match Level: the geographical level to which the address has been matched
3. Search Confidence: the quality of the matched level

This page will discuss how match levels and search confidence works.

Match level

Match level describes how well Naurt has been able to match an input address. There are four levels:

• Unit: Matched to unit level. E.g., Flat 7, 22 Ashburnham Rd, London, NW10 5SD, UK
• StreetNumber: Matched to street number level. E.g., 22 Ashburnham Rd, London, NW10 5SD, UK
• Street: Matched to the street. E.g., Ashburnham Rd, London, NW10 5SD, UK
• Postalcode: Matched to the postalcode. E.g., NW10 5SD, UK.

With each match level, Naurt will return a location from within the level though not the center.

Match level alone is usually enough information to make an informed decision about the quality of search Naurt has returned. If this is not enough, Naurt also makes available the Search Confidence.

Confidence

The confidence score is directly related to the Match Level.

• A Match Level of Unit has a maximum confidence score of 1.0 and is reduced when Naurt is unable to match and verify locality, city, or postalcode inputs.
• A Match Level of StreetNumber has a maximum confidence score of 1.0 and is reduced when Naurt is unable to match and verify locality, city, or postalcode inputs.
• A Match Level of Street has a confidence score of 0.4
• A Match Level of Postalcode has a confidence score of 0.3

Example Response with Search Level and Confidence

{
  "request_id": "31699850-447d-42d6-9e76-6da358a29d24",
  "responses": [
    {
      "additional_matches": [],
      "best_match": {
        "address": "35 Clarendon Road, Cheshunt, Waltham Cross, EN8 9DL, United Kingdom",
        "geojson": {
          "features": [
            {
              "geometry": {
                "coordinates": [-0.036495, 51.70522],
                "type": "Point"
              },
              "properties": {
                "naurt_type": "basic_geocode"
              },
              "type": "Feature"
            },
            {
              "geometry": {
                "coordinates": [[-0.036494317, 51.705280131]],
                "type": "MultiPoint"
              },
              "properties": {
                "accuracy": {
                  "quality": "high"
                },
                "naurt_type": "naurt_door"
              },
              "type": "Feature"
            },
            {
              "geometry": {
                "coordinates": [
                  [
                    [-0.0360252905826841, 51.70527881528648],
                    [-0.0365740128653158, 51.70528105243699],
                    [-0.0365748245513342, 51.70520459526901],
                    [-0.0361215508466639, 51.7052027472609],
                    [-0.0361220272710638, 51.70515787016552],
                    [-0.0360265923958014, 51.70515748107477],
                    [-0.0360252905826841, 51.70527881528648]
                  ]
                ],
                "type": "Polygon"
              },
              "properties": {
                "contributors": ["© OpenStreetMap contributors"],
                "naurt_type": "naurt_building"
              },
              "type": "Feature"
            },
            {
              "geometry": {
                "coordinates": [
                  [
                    [-0.03656098576910741, 51.70537427292737],
                    [-0.0365612671666461, 51.705351721165385],
                    [-0.0364254537653532, 51.70535107035667],
                    [-0.03642517236781451, 51.705373622119],
                    [-0.03656098576910741, 51.70537427292737]
                  ]
                ],
                "type": "Polygon"
              },
              "properties": {
                "accuracy": {
                  "quality": "high"
                },
                "minimum_parking_to_door_distance": 11.431809239026983,
                "naurt_type": "naurt_parking"
              },
              "type": "Feature"
            }
          ],
          "type": "FeatureCollection"
        },
        "id": "ab5bcc50-3d25-3c56-9ac8-0b0f1fe7f34c",
        "search_confidence": 1.0,
        "match_level": "StreetNumber"
      },
      "status": "ok"
    }
  ],
  "version": "v2.6.21-dev.21"
}