The Relative Legibility of Uppercase and Lowercase Typewritten Words
Glenn C. Kinney, Diana J. Showman · Information Display · 1967
The relative legibilities of common words typewritten in all‐uppercase and all‐lowercase letters were studied in three experiments. Human subjects identified the words shown one at a time for a short period. All‐uppercase printing was found to be significantly more legible than all‐lowercase in all three experiments. The “word‐form” of all‐lowercase words was not found to influence word identification. The use of uppercase letters is recommended for displays.