APA Dictionary of Psychology

in reading research, a procedure for stimulus presentation in which the characters of stimulus words switch between upper and lower case. The change is usually made in one of six ways: (a) to the complete word (APPLE/apple), (b) to alternate letters (ApPlE), (c) after the second letter (APple), (d) after the third letter (APPle), (e) after the fourth letter (APPLe), or (f) after each pair of letters (APplE).