Case Studies - Measuring the User Experience: Collecting, Analyzing, and Presenting Usability Metrics - page 253

corrections were needed according to the visual feedback of their fingerprint
image in relation to the overlay on the screen, but had to move their hands to
make the actual corrections on the scanner. Participants were observed being
more careful in placing their hands on the scanner in the overlay condition as
if they wanted to make sure their hands were aligned properly with the overlay,
whereas participants positioned their hands more freely in the nonoverlay con-
dition. Sixteen participants indicated that the overlay guide would be very help-
ful if it were placed on the scanner in order to align their hand on the overlay as
they placed their hand on the scanner instead of looking up and down trying to
make a perfect alignment.
We observed that participants learned to use the system very quickly. Within-
subject comparisons were performed to examine the ease of learning of the sys-
tem. When comparing the performance between Task 1 and Task 2, it was found
that Task 2 performed significantly better on RS (attempt time and errors),
RT (errors), task completion time, and total errors. Learning was even evident
within a task.
10.2.3 Conclusion
The real-time feedback fingerprint system is a highly usable system and shows
evidence of great potential for fingerprint self-captures. By following the on-
screen, real-time instructions, participants quickly learned and felt comfortable
and confident in capturing their own fingerprints without any assistance. The
next step is to determine if users will benefit more in a language-free environ-
ment in which all instructions are presented in graphical format (symbols or
icons, without any textual elements). With the findings from this study, we are
planning future research to answer this question. Although the overlay guide did
not show consistent advantages or disadvantages with respect to performance,
it was perceived as helpful with hand positioning and provided visual feedback
of where users' hands were in relation to the scanner area. Use of the overlay
guide is recommended for use in the fingerprint self-capture process; however,
we would recommend that it be placed directly on the scanner. 3
ACKNOWLEDGMENT
This work was funded by the Department of Homeland Security Science and
Technology Directorate.
REFERENCES
Guan, H., Theofanos, M., Choong, Y. Y., & Stanton, B. (2011). Real-time feedback for usable
fingerprint systems . International Joint Conference on Biometrics (IJCB), pp. 1-8.
3 The material in this chapter was taken from Y.Y. Choong, M.F. Theofanos, and H. Guan, Fingerprint
Self Capture: Usability of a Fingerprint System with Real-Time Feedback. IEEE Fifth International
Conference on Biometrics: Theory, Applications and Systems (BTAS), September 23-26, 2012.
Please refer to that paper for the complete report.