Hiring has never been easy. About two thousand years ago, officials in the Han dynasty tried to make a science of the process by creating a long and detailed job description for civil servants. Archaeological records show that those same officials were frustrated by the results of their efforts; few new hires worked out as well as expected. Today business executives trying to fill senior-level positions carry on the unhappy tradition. Using interviews, reference checks, and sometimes even personality tests, they try to infuse logic and predictability into hiring. Still, success remains elusive. Several recent surveys conducted by both business academics and independent consulting firms have found that between 30% and 50% of all executive-level appointments end in firing or resignation.