The story of subject naught: A cautionary but optimistic tale of internet survey research

In a web-based, sexual behavior risk study using a rigorous response validation protocol, we identifie 124 invalid responses out of 1,150 total (11% rejection). Nearly all of these (119) were due to repeat survey submissions from the same participants, and 65 of them came from a single participant. This brief describes how we were able to detect these repeat submissions using the validation protocol, and highlights the importance of using both automated and manual validation techniques.