At the Astrobiology Science Conference last March, Astrobiology Magazine organized a debate about alien life. Using Peter Ward's book, "Life As We Do Not Know It" as a launching pad, the participants debated everything from how to define "life" to what kind of strange aliens we can expect to find in our explorations. In part three of this seven-part series, Pam Conrad touches on the practical aspects of searching for life, while Carol Cleland takes a more philosophical approach.