Article first appeared on October 12, 2015 in: Including symbols in license plates improves recall

Including symbols in license plates improves

October 12, 2015

NEW ORLEANS – Substituting a symbol for a number in a six­character license plate was found to
significantly improve short­term recollection as compared to conventional alphanumeric­only designs,
according to a presenter here at an American Academy of Optometry­sponsored press conference.
Alan L. Lewis, OD, PhD, FAAO, and colleagues from the New England College of Optometry
evaluated the EZ­ID, a proposed license plate design that uses a heart, star, triangle or square in place
of a number or letter in a six­character license plate, as a method for making license plates more

At the press conference, Lewis shared the impetus for the proposed design change.
“A murder occurred in Massachusetts where a lot of people saw the car, but couldn’t
identify the license plate,” he said.
The researchers randomly selected 10 six­character Massachusetts license plates from a
sample of cars. Five of the plates were modified to replace one of the two middle
characters with a symbol.
Twenty­eight subjects sat 1.5 meters away from a monitor, and 10 different plates were displayed for 3
seconds each, Lewis explained.
“A distractor photo of a president was shown to get them to think about something else, then they were
asked to repeat the license plate,” he said.
“Forty­three percent of all plates were correctly identified,” Lewis said. “Sixty­one percent identified
more plates with symbols. Only 7% of plates with alphanumerics were correctly identified.”

He said that 53% of plates containing symbols and 33% of plates containing only alphanumerics were
completely correctly identified.

“Ninety­six percent of all symbols were correctly recalled,” Lewis said, “and they were always in the
right position. This is a great ability to reduce the gamut of potential vehicles with those plates.”
He concluded: “We believe the inclusion of symbols in a six­character license plate increases the recall
of a complete license number. We are moving ahead to try to convince legislators to change license
plate design.” – by Nancy Hemphill, ELS, FAAO

Disclosure: No products were mentioned that would require financial disclosure.

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