## O'Connor

The O'Connor consensus method is sometimes referred to as a Modified Mattson Method.  This system is very similar to the Mattson method, but with letters, or verbal cues assigned, and is used in the CASIE software package. The table below shows the letter assignments and their descriptions in this system.

• A - Very Likely
• B
• C - Likely
• D
• E - Even Chance
• F
• G - Unlikely
• H
• I - Very Unlikely

The letters are then assigned numerical values with a sliding scale based on the following rules:

 A = 9, B = 8, ..., I = 1 if the lowest letter used by that expert is an I. A = 8, B = 7, ..., H = 1 if the lowest letter used by that expert is an H. A = 7, B = 6, ..., G = 1 if the lowest letter used by that expert is an G. A = 6, B = 5, ..., G = 1 if the lowest letter used by that expert is an F. A = 5, B = 4, ..., G = 1 if the lowest letter used by that expert is an E. A = 4, B = 3, ..., G = 1 if the lowest letter used by that expert is an D. A = 3, B = 2, C = 1, if the lowest letter used by that expert is an C. A = 2, B = 1, if the lowest letter used by that expert is an B. A = 1, if the lowest letter used by that expert is an A.

The numerical values from the various evaluators are then averaged to determine the ranking of the various search areas.