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Interacting with mobile services: an evaluation of camera-phones and visual tags


We present a study of using camera-phones and visual-tags to access mobile services. Firstly, a user-experience study is described in which participants were both observed learning to interact with a prototype mobile service and interviewed about their experiences. Secondly, a pointing-device task is presented in which quantitative data was gathered regarding the speed and accuracy with which participants aimed and clicked on visual-tags using camera-phones. We found that participants’ attitudes to visual-tag-based applications were broadly positive, although they had several important reservations about camera-phone technology more generally. Data from our pointing-device task demonstrated that novice users were able to aim and click on visual-tags quickly (well under 3 s per pointing-device trial on average) and accurately (almost all meeting our defined speed/accuracy tradeoff of 6% error-rate). Based on our findings, design lessons for camera-phone and visual-tag applications are presented.

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  1. We chose to study these ranges of diameters and distances because we felt they were typical of those that may be encountered in tag-based interactions with mobile services (e.g. consider the plausible tag sizes and inter-tag distances that may be designed into posters).

  2. Although recorded by computer, the times were measured by the camera-phone itself. This ensured that the latency and jitter of the Bluetooth connection (used by the phone to communicate with the computer) did not affect our data.

  3. A one-way analysis of variance (ANOVA) established that the practice effect on clicking time was statistically significant (for α=0.05): F(1,17)=6.055, p=0.025.

  4. Collapsing across both sessions, linear correlation between error rate and tag diameter yielded r=−0.39, with 99% confidence intervals for ρ of (−0.554, −0.189). Note that this effect was also observed for session 1 and session 2 independently. For session 1, r=−0.30 with 99% confidence intervals for ρ of (−0.48,−0.09); for session 2, r=−0.37 with 99% confidence intervals for ρ of (−0.53,−0.17).

  5. Linear correlation between clicking time and tag diameter yielded r=0.05, with 95% confidence intervals for ρ of (−0.113,0.212).

  6. As a rule of thumb, a number smaller than 3.5 mm requires a user to hold their camera-phone closer to tags than our participants did; conversely, a number greater than 3.5 mm requires users to hold their phones further away from tags.


  1. NTT DoCoMo Unveils New mova 506i i-mode Phone Series. Press release. Available from NTT DoCoMo press center

  2. Raw data from pointing-device task. Available from

  3. Semacode website.

  4. New York Times (7th October 2004). Connecting paper and online worlds by cellphone camera

  5. Azuma RT (1997) A survey of augmented reality. Presence 6(4):355–385

    Google Scholar 

  6. Brewster SA (2002) Overcoming the lack of screen space on mobile computers. Pers Ubiquitous Comput 6(3):188–205

    Article  Google Scholar 

  7. de Ipiña DL, Mendonça P, Hopper A (2002) Trip: a low-cost vision-based location system for ubiquitous computing. Pers Ubiquitous Comput 6(3):206–219

    Article  Google Scholar 

  8. Dorfmueller-Ulhaas K, Schmalstieg D (2001) Finger tracking for interaction in augmented environments. In: Proceedings of the IEEE international symposium on augmented reality. IEEE Press, New York

  9. Fails J, Olsen D (2003) A design tool for camera-based interaction. In: Proceedings of CHI. ACM Press, New York, pp 449–456

  10. Gutwin C, Fedak C (2004) Interacting with big interfaces on small screens: a comparison of fisheye, zoom, and panning techniques. In: Proceedings of the 2004 conference on Graphics interface. Canadian Human-Computer Communications Society, pp 145–152

  11. IDC Research. Moving pictures 2003: Worldwide camera phone survey, forecast, and analysis, 2003–2007.

  12. Johnson J (1995) A comparison of user interfaces for panning on a touch-controlled display. In: Proceedings ACM CHI, pp 218–225

  13. Kato H, Billinghurst M (1999) Marker tracking and HMD calibration for a video-based augmented reality conferencing system. In: International workshop on augmented reality (IWAR), pp 85–94

  14. Kindberg T, Barton J, Morgan J, Becker G, Caswell D, Debaty P, Gopal G, Frid M, Krishnan V, Morris H, Schettino J, Serra B, Spasojevic M. People, places, things: web presence for the real world. In: Proceedings of the 3rd IEEE workshop on mobile computing systems and applications (WMCSA’00). IEEE Press, New York

  15. Kindberg T, Sellen A, Geelhoed E (2004) Security and trust in mobile interactions: a study of users perceptions and reasoning. In: Proceedings of UbiComp 2004, vol 3205 of LNCS. Springer, Berlin Heidelberg New York

  16. Krueger MW, Gionfriddo T, Hinrichsen K (1985) Videoplace—an artificial reality. In: Proceedings of the SIGCHI conference on human factors in computing systems. ACM Press, New York

  17. Bango Ltd. Bango spots link camera phones straight to mobile content. Press release, available from

  18. High Energy Magic Ltd. The spotcode framework. Available for download from:

  19. Scott MacKenzie I, Buxton W (1992) Extending fitts’ law to two-dimensional tasks. In: CHI ’92: Proceedings of the SIGCHI conference on human factors in computing systems. ACM Press, New York, pp 219–226

  20. MacKenzie IS (1991) Fitts’ law as a performance model in human-computer interaction. PhD Thesis, University of Toronto

  21. Masnik M (2004) Mobile barcode scanning catching on in Japan. The feature (2nd July 2004).

  22. Rekimoto J, Nagao K (1995) The world through the computer: computer augmented interaction with real world environments. In: ACM symposium on user interface software and technology. pp 29–36

  23. Rohs M, Zweifel P (2005) A conceptual framework for camera phone-based interaction techniques. In: Proceedings of pervasive 2005, vol 3468 of LNCS. Springer, Berlin Heidelberg New York

  24. Scott D, Sharp R, Madhavapeddy A, Upton E (2005) Using visual tags to bypass bluetooth device discovery. SIGMOBILE Mob Comput Commun Rev 9(1):41–53

    Article  Google Scholar 

  25. Sharp R (2004) New ways to maximize cameraphone technology. DeviceForge (1st July 2004).

  26. Smith M, Davenport D, Hwa H (2003) Aura: a mobile platform for object and location annotation. In: Adjunct proceedings of Ubicomp 2003

  27. Toye E, Sharp R, Madhavapeddy A, Scott D (2005) Using smart phones to access site-specific services. Pervasive Computing 4(2):60–66

    Article  Google Scholar 

  28. Want R, Fishkin KP, Gujar A, Harrison BL (1999) Bridging physical and virtual worlds with electronic tags. In: CHI ’99: Proceedings of the SIGCHI conference on human factors in computing systems. ACM Press, New York, pp 370–377

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The authors would like to thank Rob Ennals for his valuable comments and suggestions.

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Correspondence to Eleanor Toye.

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Toye, E., Sharp, R., Madhavapeddy, A. et al. Interacting with mobile services: an evaluation of camera-phones and visual tags. Pers Ubiquit Comput 11, 97–106 (2007).

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  • Mobile Phone
  • Augmented Reality
  • Mobile Service
  • Interaction Technique
  • Novice User