Face-to-face interaction via personal appearance is the only way for a Notary to properly identify the signer and look for warning signs of fraud. In a March 2010 online survey, the NNA asked Notaries what warning signs they felt were most difficult for them to spot, even when a signer is physically present. Nearly 2,000 Notaries responded. The largest percentage of participants — 36 percent — said the most difficult warning sign to spot is forged or altered identification documents. The second most common challenge, reported at 19 percent, was keying-in on clues that a signer is being coerced. Closely competing for third and fourth place respectively were spotting incomplete documents or observing that a signer didn’t understand a document, at 17 and 16 percent respectively. Detecting unusual body language from the signer received the fewest responses at 12 percent.