The science of cause and effect

An 'introduction' to causality for high schoolers, developed at the invitation of the Connecticut Academy of Science and Engineering, to contribute to their NIE (News in Education) Hartford Courant activities offerings (available on the Hartford Courant site, see http://bit.ly/causalityscience ). As with many recent 'ideas of mine' this flows directly from the wisdom of Judea Pearl (see some recent insights of his on his blog).
Comments and suggestions are welcome!