11.11.3.2 Configuring the Levels of Answer Logic

The level of Answer Logic, the intensity or strength of algorithms, used to evaluate answers given for challenge questions is adjustable.

You can enable or disable each algorithm and you can also specify the following levels for the algorithms used:

• Off: No Answer Logic is used. Answers must exactly match those provided at the time of registration.
• Low: Low level of Answer Logic is used. Answers provided by the user must be a match or near-match to the answers that were provided at the time of registration.
• Medium: More Answer Logic is used. You are given some freedom for the answers that are provided. For instance, St. is acceptable for Street.
• High: Highest level of Answer Logic is used. The constraints are not strict for matching.

Note:

The lower the setting the higher the degree of exactness required for acceptance of answers.

For example, high risk transactions such as wire transfers may require a high degree of certainty (i.e. exact match) whereas accessing personal, non-sensitive information may require a lower degree of response certainty. The following example demonstrates how the answer logic algorithm works:

Question: Who was your favorite teacher in high school?

Registered answer: Mrs. Smith

Given answer: Misses Smuth

Logic level: If set to High, the answer is accepted.

Each algorithm generates a score that represents how close the given answer is to the registered answer. You can configure OAA Admin to accept different threshold score ranges for each algorithm individually. Separate threshold values for each algorithm (low/medium/high) are set in a properties file. The default thresholds are described as follows.

Abbreviation

The values are as follows:

• Return values: 0 or 100 (no-match OR match)
• Levels: On or Off
• Logic:
  • If an abbreviation entry exists linking the given strings, score is 100.
  • Else score is 0.

Fat Fingering

The values are as follows:

• Return values: range 0 to 100
• Levels: Off, Low (90+), Medium (75+), High (60+)
• Logic:
  • If the string lengths do not match, score is 0.
  • If a position does not have the expected character or its neighbor, score is 0.
  • Else compute the number of positions that have the neighboring characters.
  • Score = (StringLength – NeighborPositionCount) * 100 /StringLength.

Phonetics

The values are as follows:

• Return values: 0, 60, 75, 90
• Levels: Off, Low (90), Medium (75), High (60)
• Logic:
  • Compute primary and alternative phonetic keys for the given strings, using DoubleMetaphone algorithm.
  • If primary keys of both strings match, score is High.
  • Else if a primary key of one of the strings and alternate key of the other string match, score is Medium.
  • Else if the alternate keys of both string match, score is Low.
  • Else the score is 0.