Letterscroll: text entry using a wheel for visually impaired users

Four text entry techniques for visually impaired users are presented. LetterScroll uses a mouse wheel to maneuver a cursor across a sequence of characters, and a button for character selection. Keystrokes per character (KSPC) vary from 6.97 to 2.68. After extensive analyses and pilot testing, two variations were chosen for initial evaluation. Method 1 (M1) uses the mouse alone to enter text. Method 4 (M4) also uses the keyboard to access vowels. In a study with seven blindfolded participants, entry rates averaged 2.9 wpm for M1 and 4.4 wpm for M4. Error rates for both methods were about 3.4%. Keywords Visually impaired, text entry, auditory feedback, voice synthesis, mouse wheel ACM Classification Keywords H5.2. Information Interfaces and Presentation, User Interfaces: Input Devices and Strategies

• Type: Conference
• Year: 2008
• Where: CHI
• Authors: Hussain Tinwala, I. Scott MacKenzie
• Keywords: CHI 2008, Entry Rates, Human Computer Interaction, Mouse Wheel Acm, Text Entry Techniques