The Truth-O-Meter at 500

SUMMARY: As we celebrate our 500th Truth-O-Meter item, we explore the candidates' records for accuracy and some of the patterns and trends we've seen.

This week marks a milestone for PolitiFact: the publication of our 500th Truth-O-Meter ruling.

Since we launched the site on Aug. 22, 2007, we've published items covering everything from gas taxes to offshore drilling, from ham and cheese sandwiches to fried squirrels.

We checked Sen. John McCain's boast that he was an early voice on global warming (True) and Sen. Barack Obama's claim that McCain said the Iraq war could go on for 100 years (False).

We examined Mike Huckabee's assertion that most of the Founding Fathers were clergymen (Pants on Fire), and Joe Biden's claims that he – not Rudy Giuliani – was the real force in reducing crime in New York City (Barely True) and (False).

PolitiFact doesn't check every statement the candidates make, only the ones we're curious about, or statements that we believe might be wrong. So when we crunched the numbers from our 500 rulings on statements from 20 candidates and more than a dozen groups, we were surprised to find our most common ruling was . . . True.

We found 29 percent were True, 17 percent Mostly True, 19 percent Half True, 12 percent Barely True, and 17 percent False.

Six percent of the statements earned our lowest rating, Pants on Fire.

A few trends and observations:

• Truth is No. 1. When we launched PolitiFact almost a year ago, we expected our most common ruling would be Half True. We figured we'd find many exaggerations that still had a germ of truth. But the campaigns have put a fair amount of effort into research and it paid off — at least in 29 percent of the items we checked. (Of course, you could see that the opposite way: 71 percent were not true. So maybe their research hasn't been so good!)

• Chain e-mails are usually wrong. PolitiFact has put a lot of emphasis on chain e-mails because we've seen them become an important source of information for many voters. We usually avoid making sweeping statements about the things we check, but we feel comfortable saying this: If you get something from a chain e-mail, it's probably wrong. Of the 27 chain e-mail claims we've checked, 20 have been False or Pants on Fire.

• Obama's and McCain's records are pretty similar. We get asked this at parties: Who has the best record? Once you accept our caveat that we don't check every claim the candidates make and we only check the ones we're curious or suspicious about, you find McCain and Obama are pretty close, with Obama having a slight edge. Obama has 34 percent True, compared with 29 percent for McCain. Seventeen percent of Obama's ratings have been False/Pants on Fire, compared with 23 percent for McCain.

(For more details on their individual records, check out our candidate pages for Obama and McCain.)

• Pants on Fire are both red and blue. Both parties have gotten their share of Pants on Fire rulings. Among candidates and party groups that have received that rating (we exclude chain e-mails and independent groups because they are not affiliated with a party), the score is Democrats 9, Republicans 7.