Art of the Problem | The search for Extraterrestrial Intelligence @ArtOfTheProblem | Uploaded 10 years ago | Updated 9 hours ago
How can we know if alien signals are intelligent? What does it mean to be intelligent? This final chapter features Carl Sagan, Phillip Morrison, Kent Cullers (SETI - The search for extraterrestrial intelligence)

Link to paper by Doyle:
web.archive.org/web/20060903080122/http://faculty.vetmed.ucdavis.edu/faculty/bjmccowan/Pubs/McCowanetal.JCP.2002.pdf