The phrase "flying saucer," so familiar to Americans and UFO buffs, is the result of a reporter’s error. After interviewing Arnold about his sighting, a reporter from the Eastern Oregonian newspaper reported that Arnold saw round, aerial objects (in fact he said they were "crescent shaped"). Arnold stated that the objects "flew erratic, like a saucer if you skip it across the water"—not that what he saw resembled an actual saucer. Yet that "saucer" interpretation stuck, prompting many eyewitnesses to repeat (and hoaxers to duplicate) Arnold’s nonexistent description. This strongly shows the role of suggestion in UFO sightings; as skeptic Marty Kottmeyer asks, "Why would extraterrestrials redesign their craft to conform to [the reporter’s] mistake?"

Further reading:

Robert Carroll. The Skeptic’s Dictionary. Available at http://www.skepdic.com/saucers.html.