SFST Test Administration 4

Question 1

When using all three SFSTs together, what is the NHTSA-validated accuracy rate for identifying subjects at or above 0.08 BAC?

Accepted Answer

91%

Answer

Using all three standardized tests together raises classification accuracy to approximately 91% per NHTSA validation studies.

Question 2

Which phase of the Walk-and-Turn test evaluates the subject's ability to divide attention between mental and physical tasks simultaneously?

Accepted Answer

Both the instruction phase and walking phase

Answer

Both phases require divided attention: the instruction phase demands balance while processing directions, and the walking phase demands balance while counting and following rules.

Question 3

During HGN testing, onset of nystagmus prior to 45 degrees is significant because it suggests:

Accepted Answer

A BAC likely at or above 0.08

Answer

NHTSA research links onset of HGN prior to 45 degrees strongly with a BAC at or above 0.08, making it the most predictive HGN clue.

Question 4

A properly standardized HGN exam consists of how many total passes of the stimulus in front of the subject's eyes?

Accepted Answer

8 passes

Answer

The standardized HGN examination involves 8 total passes: 2 for equal pupil size/resting nystagmus, 2 for smooth pursuit, 2 for maximum deviation, and 2 for onset prior to 45 degrees.

Question 5

When the subject steps off the line during the Walk-and-Turn, the officer records a clue if the subject:

Accepted Answer

Steps any distance off the designated line

Answer

Any step off the line, regardless of distance, is recorded as a clue under NHTSA standardized scoring criteria.

(SFST) Standardized Field Sobriety Testing Certified Practice Test

(SFST) Standardized Field Sobriety Testing Certified Practice Test

SFST Test Administration 4