By age 4 or 5, many children can identify letters.

A special word page at the end of each book provided extra practice in identifying letters and words.

Then they went through another round of tests in which they were to identify letters superimposed on the dots as they moved across the screen.

Children can learn to construct simple words and sentences and identify shapes, letters and numbers.

Printed inside the frames-innocuously, like serial numbers-was a series of four telephone numbers and identifying letters.

The letters under the "Version" column are identifying letters used by historians to refer to these manuscripts.

A positive diagnosis results from a patient's inability to correctly identify shapes or letters projected simultaneously in different areas of the screen.

All these tricks are attempts to disguise the boundaries of the characters, so that software cannot identify the numbers and letters.

When identifying letters while reading, not only are their shapes picked up but also other features like their colors and surrounding elements.

"Too many people think rote learning, identifying letters and numbers, are signs of school readiness," she said.