What is a false positive?
A false positive occurs when spam filtering or spam blocking techniques wrongly classify a legitimate email message as spam and as a result interferes with its delivery. The opposite, a false negative, occurs when filtering allows a spam email to be delivered to a user’s inbox. While most anti-spam tactics can block or filter a high percentage of unwanted emails, doing so without creating significant false-positive results is a much more demanding task.
During a screening, if the test detects a drug it is called a non-negative or “presumed” positive. If the drug detected is one you are taking through prescription at your doctor’s orders, it is a negative, or negated positive. Some over-the-counter medications will preliminarily test non-negative (positive), but the confirmatory tests will rule out any non-illicit substances. What is generally called a “false” positive is simply a result which has not been confirmed.
