Contrary to popular belief, standardized field sobriety tests are not "pass - fail." The tests are designed to look for clues of intoxication due to not having the normal use of your mental or physical capabilities due to the introduction of alcohol or some other substance into your body. Field sobriety test are difficult to perform under even the most ideal circumstances. Failing to attempt to perform field sobriety tests will be taken as though you are trying to hide evidence of guilty, but attempting to perform field sobriety tests will most likely create some evidence of guilt in a DWI. Whether you agree to perform a sobriety test or not, make sure to tell the police officer about any chronic or recent injuries to your feet, ankles, knees, hips, back or brain (such as a concussion), because these types of injuries can affect your balance.