Page 70 - THE DUTCH TALKING TOUCH SCREEN QUESTIONNAIRE

Chapter 3
All four participants were able to fill out the DTTSQ autonomously in approximately 5 minutes, which was fairly acceptable to them. Three of them used the read aloud function. They used neither the help nor the escape functions. Two users indicated they had missed a back function. The help function was hard to understand for the participants. All screens contained a help button, which activated an overlay of the current screen. The overlay provided written information and instruction, an explanation of all the buttons on the screen, and a movie of a host providing spoken information and instruction. Participants were confused by the multitude of information. Also, they did not understand that the overlay was not interactive and that they had to return to the original screen in order to carry out the instruction. Participants did not use the escape function, since they did not understand the meaning of the symbol that was chosen for this button (an exclamation mark in a triangle). However, all users appreciated the function and advised to use a traffic stop sign instead.
Figure 3.3 Help function as an overlay to the current screen, with written information and instruction, explanation of buttons, and access to a movie of a host (movie icon, bottom left). Top right: read aloud button and help button. Bottom left: escape button (triangle with exclamation mark)
Implementation phase: final design. On the basis of the usability evaluation the final design of the DTTSQ was created (see Fig 3.4- Fig. 3.9 for a selection of screens). The original help function was deleted and the read aloud function was turned into a help function. The help button
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