How is the accuracy of field sobriety tests generally measured?

The accuracy of field sobriety tests is generally measured by statistical analysis of test results. This method involves collecting data on the outcomes of multiple tests administered in various conditions and contexts, followed by using statistical techniques to evaluate the tests' reliability and validity in predicting impaired driving. Statistical analysis provides a systematic way to assess performance and determine how well these tests can differentiate between sober and impaired individuals.

In contrast, anecdotal evidence lacks the rigor and reproducibility needed for reliable conclusions. Similarly, relying solely on an officer's personal judgment may introduce bias and individual variability, which can compromise the objectivity necessary for accurate assessments. Self-reported assessments by the subjects also do not provide an unbiased measure of impairment, as individuals may not have an accurate perception of their own level of intoxication. Thus, statistical analysis serves as the most credible and scientifically robust method for measuring the accuracy of field sobriety tests.