Page 137 - THE DUTCH TALKING TOUCH SCREEN QUESTIONNAIRE

Evoluation of the Dutch and Turkish version
occurred, but also what caused these problems to occur and what effect encountering the problems had on participants. In addition, this method suited the needs of low educated and low literate participants by not demanding any reading or writing skills from them. A downside of the chosen method is the lack of generalizability of the data.
A limitation of this study was that participants were encouraged by the interviewer to try touching the screen again when they looked startled because it did not react to their initial touch. This may have influenced the results on effectiveness because it is unknown what would have happened if the interviewer would not have interfered. This may vary from no effect, because the participant would have tried it again anyway, to a higher frequency of occurrence of problem 8, to more participants prematurely stopping to complete the DTTSQ because of being under the impression that the application had stopped working. Any kind of interference in the process of usability testing has a direct influence on the effectiveness results and possibly also on the efficiency and satisfaction results and should therefore be avoided.
Conclusions
The usability of the DTTSQ needs to be improved before it can be released. No problems were found with satisfaction or efficiency during the usability-test. Effectiveness needs to be enhanced by 1. making it easier to navigate through screens without the possibility of accidently skipping one, 2. enable the possibility to insert an answer by tapping on the text underneath a photograph instead of just touching the photograph itself and 3. making it easier to correct wrong answers. Participants additionally recommended to minimize the length of the instructions and present all the answer options of question 4 in one screen.
Directions for future research
During further development of the DTTSQ both the results of the current study and the study on response process of the DTTSQ [36] should be taken into account simultaneously. The usability and the response processes will have to be re-tested in exactly the same manner after adjustments in the DTTSQ have been made. This process will have to be repeated until an acceptable level of usability and face validity of the DTTSQ is reached. The next step in research should be quantitative usability-, validity- and reliability testing producing
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