Improvements in image understanding technologies are
making it possible for computers to pass traditional
CAPTCHA tests with high probability. This suggests the
need for new kinds of tasks that are easy to accomplish
for humans but remain difficult for computers. In this
paper, we introduce Fluency CAPTCHA (FluTCHA), a
novel method to distinguish humans from computers
using the fact that humans are better than machines at
improving the fluency of sentences. We propose a way
to let users work on FluTCHA tests and simultaneously
complete useful linguistic tasks. Evaluation studies
demonstrate the feasibility of using FluTCHA to
distinguish humans from computers.
The HCIL has a long, rich history of transforming the experience people have with new technologies. From understanding user needs, to developing and evaluating these technologies, the lab's faculty, staff, and students have been leading the way in HCI research and teaching.