APPENDIX A
COMBINED TEST SCORING PROCEDURE
[Post-publication note (August 1999): This matrix is no longer used in SFST training materials.]
Horizontal Gaze Nystagmus Test Score
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0 |
1 |
2 |
3 |
4 |
5 |
6 |
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Walk |
0 |
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1 |
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& |
2 |
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3 |
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Turn |
4 |
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5 |
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Test |
6 |
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7 |
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Score |
8 |
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9 |
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The above matrix utilizes the combined test scores for the horizontal gaze nystagmus test and the walk and turn test. If the box at the intersection of a subject’s horizontal gaze nystagmus and walk and turn test scores is shaded, a subject’s blood alcohol content is predicted to be .10%. Data showed that the accuracy of law enforcement officers correctly classifying subjects as above or below .10% blood alcohol content is 80% using this matrix.