Word shape is the overall visual impression of the outer boundary of a given word. Word shape is attributed as one of the key factors in readability and is widely considered the reason that Lowercase words are more readily recognizable than their Uppercase equivalent. The belief is that because uppercase words always have a rectangular word shape they are less distinct than lowercase words which have a varying word shape, given definition by ascenders and descenders that create unique, and therefore more recognizable shapes.
Word shape is believed to be one of the two probable ways that information is processed by the eye. Researchers are divided between word shape recognition and letter identification as the process by which information is processed during reading.
See also readability.