NEW YORK (CNN) - Unemployment is a key issue in this year's election, particularly in battleground states like Ohio, where both candidates have addressed job loss in stump speeches.

Kerry prefers payrolls data.

But President Bush and Sen. Kerry disagree over whether Bush has overseen a net loss of jobs during his presidency, each citing numbers from the Bureau of Labor Statistics to support their claims.

In another case of spinning the numbers, both candidates are technically correct.

Kerry regularly claims that Bush will be the first president since Herbert Hoover to oversee a net loss in jobs during his administration, citing data from a monthly Bureau of Labor Statistics (BLS) report known as the "payroll survey."

And according to the payroll survey, since Bush took office the U.S. has suffered a net job loss of about 600,000 to 800,000 jobs.

Bush prefers households data.

Bush cabinet members Snow and Evans argue that the nation has actually gained jobs under Bush, according to data from a monthly BLS report known as the "household survey."

And according to the household survey, the nation has created a net job gain of 1.7 million, making the Bush camp right.

So which is more accurate, payroll or household?

According to Bureau of Labor Statistics, the payroll survey is a more accurate measure of job loss than the household survey, but both surveys have limitations.

The payroll survey does not cover self-employed workers, while the household survey does, so when Kerry cites all the jobs lost, that doesn't mean all of those people are necessarily unemployed.

While the household survey was not designed to measure the raw number of jobs at any given moment, it was specifically designed to measure the unemployment rate.

The payroll survey was designed to measure the raw number of jobs in a given month, and it is more widely used to measure job loss.

John Snow told the Courier newspaper in Ohio, "Claims like the one that Bush will be the first president to end a term with fewer jobs than when he started are nothing more than 'myths.' "

A narrator in a recent Kerry campaign ad responded by saying, "How out of touch is George Bush with Ohio? Over the last four years, we've lost over 230,000 jobs in our state. Now George Bush sends his treasury secretary to Ohio to tell us these job losses are a 'myth.' Do you think it's a myth that we've lost jobs?

"Over 100,000 Ohioans have lost their health insurance. Family incomes have fallen by $1,500. When is George Bush going to face reality?"

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CNN fact checkers say Kerry accurately calculates the number of jobs lost based on payroll figures, which is actually about 237,000.

However, the claim that 100,000 Ohioans have lost health insurance is misleading, because this incorrectly implies that all 100,000 once had health insurance and have since "lost" it since Bush took office.

It is true that there are 114,000 more uninsured Ohioans since Bush came to office, according to U.S. Census Bureau figures, but the Census does not track the number of people who have "lost" their health insurance.