Numerical Scoring

Rules

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• 3- /7-Position Scoring Rules

  • Step 1: Determine whether the physiological recordings are suitable for scoring. If not, do not score.
  • Step 2: Channel by channel, directly compare phasic responses at the relevant question to those at the appropriate probable-lie comparison question.
  • Step 3: If the more significant reaction is associated with the relevant question, negative scores are assigned. Positive scores are assigned if the larger reaction occurs to the probable-lie comparison question.
  • Step 4: If the difference between the reactions to the relevant and comparison questions is noticeable, it receives a score of +/-1. The sign, plus or minus, depends on which question has the larger reaction. If using the 3-position scoring system, skip Steps 5-6.
  • Step 5: If the difference between the reactions to the relevant and comparison questions is significant, it receives a score of +/-2. The sign, plus or minus, depends on which question has the larger reaction.
  • Step 6: If the difference between the reactions to the relevant and comparison questions is dramatic, it receives a score of +/-3. The sign, plus or minus, depends on which question has the larger reaction.
  • Step 7: Sum all of the scores. Decision rules for the prominent systems are listed to the right.

• 7-Position Decision Rules

  Single-Issue Examinations

  Backster
  Total scores for 2 relevant questions

  # of Charts	NDI	DI
  2	≥ +5	≤ -9
  3	≥ +7	≤ -13
  4	≥ +9	≤ -16

  Total scores for 3 relevant questions

  # of Charts	NDI	DI
  2	≥ +7	≤ -13
  3	≥ +10	≤ -19
  4	≥ +13	≤ -25

  Federal
  Criteria for DI (3 charts, 3 RQs)

  • Sum of scores for all questions is -6 or lower, or;
  • Any spot score is -3 or lower

  Criteria for NDI (3 charts)

  • Sum of scores for all questions is +6 or greater, and;
  • Every spot score is greater than 0

  Utah
  Criteria for DI (3-5 charts, 3 RQs)

  • Sum of scores for all questions is -6 or lower.

  Criteria for NDI (3-5 charts)

  • Sum of scores for all questions is +6 or greater

  Multiple-Issue Examinations

  Backster
  Minimum spot scores

  # of Charts	NDI	DI
  2	≥ +3	≤ -5
  3	≥ +4	≤ -7
  4	≥ +5	≤ -9

  Federal
  Criteria for DI (3 charts)

  • A spot score of -3 or lower produces a result of DI for that question, or;
  • At least one spot score is -3 or lower

  Criteria for NDI (3 charts)

  • Every spot score is +3 or greater

  Utah
  Criteria for DI (3-5 charts)

  • A spot score of -3 or lower produces a result of DI for that question, or;
  • Sum of scores for all questions is -6 or lower, and;
  • Every spot score is less than 0

  Criteria for NDI (3-5 charts)

  • A spot score of +3 or greater produces a result of NDI for that question, or;
  • Sum of scores for all questions is +6 or greater, and;
  • Every spot scores is greater than 0

• Rank Order Scoring System

  • Step 1: Determine whether the physiological recordings are suitable for scoring. If not, do not score.
  • Step 2: Count the number of relevant and comparison questions. The largest rank is equal to that number. For example, the Federal ZCT has 3 relevant and 3 comparison questions, for a total of 6. The largest rank for the Federal ZCT is 6. The lowest rank is 1, for all testing techniques.
  • Step 3: Beginning with the pneumograph, assign ranks to each question, beginning with the largest reaction. Do the same for the electrodermal and blood pressure channels. Continue through all of the charts. Artifacted recordings receive the lowest ranks.
  • Step 4: Sum all of the ranks for the relevant questions, and then sum all of the ranks for the comparison questions.
  • Step 5: Subtract the sum of ranks from the relevant questions from the sum of ranks for the comparison questions. This produces the final score (C - R = score).
  • Step 6: If a single-issue examination was conducted with three relevant and three comparison questions, one can use cutting scores that were empirically established and cross-validated. Scores equal to or greater than -1 are called NDI. Scores equal to or lower than -13 are DI. All others are inconclusive. Cutting scores for multiple issue examinations have not been determined.

• Other Decision Rules

  Objective Scoring System
  Criterion for DI (3 charts)

  • Sum of scores for all questions is -8 or lower

  Criterion for NDI (3 charts)

  • Sum of scores for all questions is +8 or greater

  Lykken Scoring
  Criterion for DI

  • If sum of scores is equal to, or greater than the number of Concealed Information Tests

  Criteria for NDI

  • If the sum of scores is less than the number of Concealed Information Tests