___________ literally means "blow against the state."

Which model of public policy weighs costs and benefits, and helps select those producing the greatest benefits over costs?

A) rational B) institutional C) group D) incremental

While participating in a lengthy experiment involving job training for welfare recipients, the economy enters into a major recession. Posttest measurements found that job training was unsuccessful in helping participants locate jobs. However, the experiment's designers claim that the findings were inconclusive because of internal invalidity. Which of the following sources of internal invalidity would they be most likely to name as the problem?

A. contamination B. history effect C. selection bias D. the Hawthorne effect