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The Effects of Touch Screen Technology on the Usability of E-Reading Devices

Eva Siegenthaler, Yves Bochud, Pascal Wurtz, Laura Schmid, and Per Bergamin

Journal of Usability Studies, Volume 7, Issue 3, May 2012, pp. 94 - 104

Article Contents


Results

Statistical analysis was performed using F-statistics based on a repeated measures ANOVA with the within factor “reading device” (Sony PRS-505, Sony PRS-600, Apple iPad). In cases of unequal variances within the groups, Friedman tests (using x2-statistics) were employed.

Use Cases

The percentage of task completion is summarized in Table 3. On average, on every device, each task was completed by more than 90% of the participants within the time window of two minutes.

Table 3. Usability Tasks: Percentage of Successful Task Completion

Table 3

The time required for successful task completion is shown in Table 4. On these completion times, a repeated measures ANOVA with the within factor device was computed. A critical p<0.05 was used for statistical significance in all analyses. Huynh-Feldt adjustment was used in correcting for violation of sphericity when necessary to adjust non-uniform variances.

For five out of seven tasks no significant differences were found between the devices.

Table 4. Usability Tasks: Mean Time in Seconds Required To Solve the Task*

Table 4

Usability Ratings

The following sections discuss the design, navigation, handiness, handling, and questionnaire results of this study. Participants were asked to evaluate each device using a Likert-type scale from 1 (very bad) to 6 (very good).

Design

Participants were asked “How do you like the design?” The ratings about the design of the reading devices was significantly different between devices, x2 (2, N=12) = 10.4, p < .01. Results of the subjective ratings are shown in Table 5. Post-hoc tests (Wilcoxon-test) showed that the design rating for the Sony PRS-505 was significantly worse than the ratings for the two other devices.

Navigation

Participants were asked “How do you judge the navigation?” We found significant differences between the devices, x2 (2, N=12) = 10.867, p < .01. Table 5 shows the mean ratings. Post-hoc tests (Wilcoxon-test) showed that the navigation rating for the Sony PRS-505 was significantly worse than the ratings for the two other devices.

Handiness

Participants were asked “How handy do you rate the reading device?” We found significant differences in handiness of the reading devices, x2 (2, N=12) = 11.529, p < .01. Table 5 shows the mean ratings. Post-hoc tests (Wilcoxon-test) showed that the handiness rating for the Sony PRS-600 was significant better than the ratings for the two other devices.

Handling

Participants were asked “How easy was it for you to handle the reading device?” We did not find significant differences in manageability between the reading devices, x2 (2, N=12) = 4.941, p = .085. Table 5 shows the mean ratings.

Table 5. Usability Questionnaire: Mean Rating*

Table 5

Usability questionnaire

We did not find significant differences between the usability questionnaire based on the questionnaire by Huang, Wei, Yu, and Kuo (2006); x2(2, N=12) = 1.512, p = .469.

 

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