Findings Concerning CAPTCHA Indignity
There are nine images. Three of them have a traffic light. Or four. The edge case is a pole. The question is whether a pole is a traffic light.
Subject: The CAPTCHA Classification: Preliminary forensic findings Status: Human, pending edge case review
The test was initiated by a website seeking to verify that the person attempting to log in was not a bot. The test is a reasonable safeguard. The test asked about traffic lights.
The Evidence
Nine images were presented. Three clearly contained traffic lights. Two clearly contained no traffic lights. The remaining four contained: a partial view of a signal housing obscured by a bus, a pole whose top half was cut off by the image boundary, a street corner containing what appeared to be a signal but which could also be a decorative fixture, and an image that was blurry enough that its contents were a matter of interpretation.
The person completing the test selected the three unambiguous traffic lights and one of the ambiguous cases, which seemed more like a traffic light than the others.
The test said: please try again.
The Interpretation
A second set of nine images was presented. The edge cases in this set involved bicycles, where the line between bicycle and scooter became relevant. The person selected the objects that were more bicycle than not. The test said: please try again.
A third set was presented. The person selected all bicycles and one scooter that was definitely not a bicycle but which, given the pattern of prior failures, seemed like an object the test wanted selected.
The test accepted this selection. The person was logged in.
The Findings
The test is designed to distinguish human from automated responses. Automated responses are consistent. Human responses are inconsistent. The test appeared to be testing for inconsistency as the marker of human behavior.
The person passed by selecting an object they knew was wrong. The test found this credible. Whether this says something about the test, or about humans, or about both, is left as an open question.
They are logged in. They are probably human.