Across the country, state education officials are asking whether tests of general knowledge and specific subjects are rigorous enough to ensure that only able candidates become teachers. One test, for example, asks the taker to put World War I, the start of the Great Depression, the New Deal and the Korean War in the correct chronological order.

• Some 35 states use a test called Praxis I -- developed by the Educational Testing Service -- or more advanced tests in the Praxis series to certify graduates for general knowledge, professional skills and subject knowledge.

• Virginia's Gov. James S. Gilmore reported this month that as many as one-third of would-be teachers in his state flunked the test.

• Since Virginia has the country's highest cutoff score for Praxis I, experts say scarcely half the teaching students nationwide who took the test would have made the Virginia cut.

• Some states have their own tests and some are only now beginning to adopt standards for certification as a teacher.

In October, New Hampshire's board of education voted to adopt Praxis I starting this fall, after years of opening the profession to anyone with a college teaching degree. However, Democratic Gov. Jeanne Shaheen vetoed legislation that would have required the test for teachers already on the job.

In Pennsylvania, education officials are beginning to raise the bar for a number of tests. After almost 91 percent of would-be teachers passed a 120-question general test for beginning teachers last fall, officials began to question the value of the test.

Some state officials argue that high standards conflict with the need to staff schools in some difficult rural and inner-city areas. North Carolina had to back off from higher standards several years ago and Mississippi is debating waivers for candidates who don't make its cutoff points. Florida has allowed waivers.