Theresa Sinclair may be a rare specimen -- someone who came forward seeing something in the sky that she couldn't explain.

About 6:30 a.m. March 23, the 58-year-old Silvis woman spotted a bright, triangular object speeding through the sky.

Afterwards, she was willing to talk to a reporter about what she saw, though she said she had no idea what she actually saw.

"This lady's very brave," said Joe Leto, the head of DIEPART, a Des Moines group that investigates the unexplained. "She's obviously very confident and very secure in what she saw."

People who see -- or think they see -- something strange often won't talk to agencies like the police, or the mainstream media, because they are afraid people will think they are crazy, he said.

"Since about 2000, in Iowa, there have been over 200 sightings like this," Mr. Leto said. He said the most recent case his group investigated in the Quad-Cities area was about two months ago.

But the Rock Island and Scott county sheriff's departments said it is unusual to receive calls about unidentified flying objects.

"We rarely get them," Rock Island County Sheriff Mike Huff said. "The last time we got them, we believe they were connected to a large display of what is called the Northern Lights."

That happened a few years ago, he said.

"I don't know if we can remember when we've got a call like that,"

Maj. Mike Brown of the Scott County Sheriff's Office said.

But people do see things they can't explain, and there is interest in their accounts. Enter "UFO" into Yahoo.com's search function and there are millions of hits.

Some local educators believe the interest stems from a desire to classify the unknown, because the unknown can be frightening.

"We're obviously not going to be able to tell if what she saw is a UFO or not," said professor Mark Vincent, who teaches psychology at Augustana College, of Ms. Sinclair's account. "I think people are always trying to construct explanations for their observations."

In modern culture, people know what a UFO is; references abound in the mass media, so they can be a possible explanation for any unexplained sighting.

Though it's not surprising people can come to that conclusion, those conclusions aren't always based in fact, Mr. Vincent said.

Sometimes the brain plays tricks on the witness.

The human brain tends to see order in things even when it's not there, said Ian Harrington, a biological psychologist, also in the Augustana psychology department.

If the brain does not have complete information, it still tries to make sense of what it has, he said. It might form connections that aren't really there, making something that could actually be mundane into something extraordinary.

"The brain can't help itself," Mr. Harrington said. "The brain is desperately trying to make sense of things all the time."

To where someone's brain leads that person is up to that individual, he said. Some might see a UFO, yet others might just see aircraft, he said.

What happened to Ms. Sinclair can happen to anyone, said Bruce D. LeBlanc, a sociology and psychology professor at Black Hawk College.

"I think anything's possible for any human being to experience," he said.

Though some people who see the unexplainable are mentally ill, others exhibit no signs of illness, he said.

Mr. LeBlanc added it is also possible for someone to see something that exists, but that cannot be measured with existing science and technology.

DIEPART will try to investigate any accounts of the unexplainable that people bring to it, Mr. Leto said. The group is going to look into Ms. Sinclair's account.

"We're going to see if we can basically debunk it," he said, adding they are "not trying to make her a fool or anything."

It's possible what she saw was something ordinary like an airplane, or possibly it was a hoax, he said.

But Mr. Leto said he does not think it is the latter, because hucksters usually try to pull those off with more people around.

"Maybe, actually, she saw something," he said. "I'm just not sure."