Procedure:
(1) The person is asked to recite the alphabet, sometimes starting at "C" or another letter.
(2) The person should not sing the alphabet.
Clues to possible intoxication:
(1) skipping a letter
(2) repeating a letter
(3) giving an incorrect letter in the sequence
(4) forgetting where in the alphabet that the person is
(5) slurred speech
Interpretation:
• minimum number of clues: 0
• maximum number: quite a few
• The presence of one or more clues is considered a positive test.
Variations:
(1) reciting the alphabet in reverse. This is not recommended since this may be a problem for nonintoxicated person (a failure does not distinguish normal from abnormal).
(2) clapping hands while reciting the alphabet
(3) alphabet with examiner finger snaps (subject recites alphabet and observer randomly snaps his or her fingers which the subject must acknowledge without interrupting the alphabet sequence)
Limitations:
• The test may not be reliable if the subject is not a native English speaker.
• Antihistamines and sedative can result in slurred speech.
• While most subjects are correctly classified, some intoxicated persons pass while some nonintoxicated persons fail. Therefore the test has limited use by itself, but it can be used to screen suitable candidates for alcohol testing.
