Tiers & Confidence Scores

Tiers & Thresholds

Tiers and Thresholds are terms used to classify the degree to which an existing biometric template matches a currently captured one. Thus, this terms are used for Identification and Verification workflows.

The Threshold is a project configuration done in Simprints ID servers, and can be adjusted to affect the outcome of the resulting matched beneficiaries. Thus Simprints ID uses the specified Thresholds to determine if a potential matching biometric record is worthy of being added to the candidate list. For more information on Tiers and Thresholds, have a look at the IDb4Enrol section here.

The Tier is an enum with 5 values indicating the rankings, and can be accessed using the getTier method of the Identification or Verification objects.

public enum Tier {

    TIER_1,    // Almost certain match   (the biometrics are very similar)
    TIER_2,    // Very good match
    TIER_3,    // Good match
    TIER_4,    // Okay match
    TIER_5,    // No match               (the biometrics are very different)
}

// accessing the value

Tier tier = identification.getTier()

Confidence Scores

The confidence score is a numerical value that indicates the likelihood of a match. The returned number is dependent on the biometric modality selected. The confidence score adapts over time, as the match results become more accurate.

// accessing the value
float score = verification.confidence