SFST Study Guide
How many inches should the stimulus be held from the suspect's face when administering the HGN test?
- Answer-12-15 inches
What is the minimum number of seconds that the stimulus should be held when checking for nystagmus
at maximum deviation? - Answer-4
What is the minimum pace (in seconds) that the stimulus should move when checking for the onset of
nystagmus prior to 45 degrees? - Answer-4
What is the recommended order that the SFST's should be administered? - Answer-HGN, walk-and-turn,
one leg stand
True or False: If any one of the standardized field sobriety test elements is changed, the validity is
compromised. - Answer-True
Which type of nystagmus is an indicator of high BAC level for the impaired person OR an indication that
they are under the influence of drugs? - Answer-Vertical Gaze Nystagmus
How many total clues in the HGN are needed to indicate a test failure? - Answer-4 out of 6
Based upon the original research, how accurate is HGN? - Answer-77% for .10 and 88% for .08
, True or False: If a suspect is wearing high heels (2" or higher) an officer should provide them with the
option of taking them off when performing the walk and turn test? - Answer-True
What is the total number of inches that must be between heel and toe in order to be considered a clue
during the walk and turn test? - Answer-1/2"
What is the minimum number of inches that the hands/arms must deviate from the sides of the body
during the walk-and-turn in order to be considered a "clue" of impairment? - Answer-6
List the six (6) valid clues of the HGN test: - Answer--Lack of smooth pursuit in each eye (2 total clues)
-Distinct & sustained nystagmus at maximum deviation (2 total clues)
-Onset of nystagmus prior to 45 degrees (2 total clues)
List the eight (8) valid clues of the WAT test: - Answer--Can't balance during instruction phase
-Start to soon
-Stop while walking
-Misses heel-to-toe (by ½ or more)
-Steps off line
-Uses arms to balance (6" or greater from side)
-Improper turn
-Takes other than 9 steps
What is the minimum number of clues on the WAT test indicate a BAC above .10 68% of the time? -
Answer-2 or more
List the four (4) valid clues of the OLS test: - Answer--Sway while balancing
-Uses arms to balance
How many inches should the stimulus be held from the suspect's face when administering the HGN test?
- Answer-12-15 inches
What is the minimum number of seconds that the stimulus should be held when checking for nystagmus
at maximum deviation? - Answer-4
What is the minimum pace (in seconds) that the stimulus should move when checking for the onset of
nystagmus prior to 45 degrees? - Answer-4
What is the recommended order that the SFST's should be administered? - Answer-HGN, walk-and-turn,
one leg stand
True or False: If any one of the standardized field sobriety test elements is changed, the validity is
compromised. - Answer-True
Which type of nystagmus is an indicator of high BAC level for the impaired person OR an indication that
they are under the influence of drugs? - Answer-Vertical Gaze Nystagmus
How many total clues in the HGN are needed to indicate a test failure? - Answer-4 out of 6
Based upon the original research, how accurate is HGN? - Answer-77% for .10 and 88% for .08
, True or False: If a suspect is wearing high heels (2" or higher) an officer should provide them with the
option of taking them off when performing the walk and turn test? - Answer-True
What is the total number of inches that must be between heel and toe in order to be considered a clue
during the walk and turn test? - Answer-1/2"
What is the minimum number of inches that the hands/arms must deviate from the sides of the body
during the walk-and-turn in order to be considered a "clue" of impairment? - Answer-6
List the six (6) valid clues of the HGN test: - Answer--Lack of smooth pursuit in each eye (2 total clues)
-Distinct & sustained nystagmus at maximum deviation (2 total clues)
-Onset of nystagmus prior to 45 degrees (2 total clues)
List the eight (8) valid clues of the WAT test: - Answer--Can't balance during instruction phase
-Start to soon
-Stop while walking
-Misses heel-to-toe (by ½ or more)
-Steps off line
-Uses arms to balance (6" or greater from side)
-Improper turn
-Takes other than 9 steps
What is the minimum number of clues on the WAT test indicate a BAC above .10 68% of the time? -
Answer-2 or more
List the four (4) valid clues of the OLS test: - Answer--Sway while balancing
-Uses arms to balance
