FREE for use with an Inquisit Lab or Inquisit Web license.
This script shows Tversky & Kahneman's framing effect, in which the effective values of equal propositions change depending on whether they are framed as a loss or a gain.
Tversky, A. & Kahneman, D. (1981). "The framing of decisions and the psychology of choice".
Science 211 (4481): 453-458.