group of 10 pairs (labeled 1–10) to the second (labeled A–K; an 11th pair with a different number of land impressions was inserted in this group). Roberge and Beauchamp (2006) exploited the pairwise nature of the test samples to create a training set of known matches; this gave them a sense of optimal “Max Phase” scores (see Chapter 4) to use as a decision rule and assign matches. Following the training phase, the testing was performed stage-wise—performing a set of comparisons, applying decision rules to pick out matches, removing those elements from the dataset, and repeating—until all assignments were made.

Though a caption in Dillon (2005:10) touted BulletTRAX-3D (and its companion MatchPoint Plus display stations) as “the latest configuration of IBIS”—suggesting a replacement of IBIS—the system was originally positioned as a counterpart to IBIS. However, FTI has recently indicated a shift of its product line to focus on three-dimensional platforms, shifting the two-dimensional system currently deployed as the base for the NIBIN-system as the “IBIS Heritage” branch (see Box 4-1). Promotional materials for the three-dimensional systems emphasize that the three-dimensional systems are backward-compatible with the older two-dimensional systems; photographs are taken during the two-dimensional acquisition process and are offered as a layer that can be viewed onscreen in the three-dimensional system, so that photographs can presumably be subjected to the existing two-dimensional comparison process. It is unknown what changes have been made to account for three-dimensional measurement information in generating comparison scores in these new systems.



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