Xiaojun Bi

Google Inc. / Stony Brook University

Email: xjunbi at gmail.com


I will join the Department of Computer Science at Stony Brook University as an Assistant Professor in December 2016.
I am currently looking for highly motivated students to kick-start my research lab at Stony Brook. Feel free to drop me an email if you are interested.



| Brief Biography | Publications | Research Highlights | Patents | Teaching | Professional Services | Curriculum Vitae |


Refereed Publications

UIST 2016

[23]. Xiaojun Bi, Shumin Zhai (2016) "Predicting Finger-Touch Accuracy Based on the Dual Gaussian Distribution Model". In Proceedings of UIST 2016 - The ACM Symposium on User Interface Software and Technology. To appear. [Acceptance Rate: 20.6%]

Paper


CHI 2016

[22]. Xiaojun Bi, Shumin Zhai (2016) "IJQwerty: What Difference Does One Key Change Make? Gesture Typing Keyboard Optimization Bounded by One Key Position Change from Qwerty". In Proceedings of CHI 2016 - the SIGCHI Conference on Human Factors in Computing Systems. 49 - 58. [Acceptance Rate: 23.4%]

Paper


CHI 2016

[21]. Chun Yu, Hongyi Wen, Wei Xiong, Xiaojun Bi, Yuanchun Shi (2016) "Investigating Effects of Post-selection Feedback for Acquiring Ultra-Small Targets on Touchscreen". In Proceedings of CHI 2016 - the SIGCHI Conference on Human Factors in Computing Systems. 4699 - 4710 [Acceptance Rate: 23.4%]

Paper


CHI 2015

[20]. Brian Smith*, Xiaojun Bi, Shumin Zhai (2015) "Optimizing Touchscreen Keyboards for Gesture Typing". In Proceedings of CHI 2015 - the SIGCHI Conference on Human Factors in Computing Systems. 3365-3374 [Acceptance Rate: 23%]

*Brian Smith was a research intern supervised by Xiaojun Bi at Google. | Paper


CHI 2015

[19]. Andrew Fowler, Kurt Partridge, Ciprian Chelba, Xiaojun Bi, Tom Ouyang, Shumin Zhai (2015) "Effects of Language Modeling and its Personalization on Touchscreen Typing Performance". In Proceedings of CHI 2015 - the SIGCHI Conference on Human Factors in Computing Systems. 649-658 [Acceptance Rate: 23%]

CHI 2015 Honorable Mention Award (Top 5%) | Paper


CHI 2014

[18]. Xiaojun Bi, Tom Ouyang, Shumin Zhai (2014) "Both Complete and Correct? Multi-Objective Optimization of Touchscreen Keyboard". In Proceedings of CHI 2014 - the SIGCHI Conference on Human Factors in Computing Systems. 2297-2306 [Acceptance Rate: 22.8%]

Paper


Human-Computer Interaction 2014, Volume 29

[17]. Xiaojun Bi, Seok-Hyung Bae, Ravin Balakrishnan.(2014) "WallTop: Manage Overflowing Windows on a Large Display", Human-Computer Interaction. Volume 29, Issue 2, 153-203. [2014 Impact Factor: 3.143]

Author's Accepted Manuscript, Version of Record at Taylor and Francis| Video


CHI 2013

[16]. Xiaojun Bi, Yang Li, Shumin Zhai (2013) "FFitts Law: Modeling Finger Touch with Fitts' Law". In Proceedings of CHI 2013 - the SIGCHI Conference on Human Factors in Computing Systems. 1363-1372 [Acceptance Rate: 20%]

Google 2013 Influential Paper Award | Paper



CHI 2013

[15]. Xiaojun Bi, Shiri Azenkot, Kurt Partridge, Shumin Zhai (2013) "Octopus: Evaluating Touchscreen Keyboard Correction and Recognition Algorithms via Remulation ". In Proceedings of CHI 2013 - the SIGCHI Conference on Human Factors in Computing Systems. 543-552 [Acceptance Rate: 20%]

Paper | Video



UIST 2013

[14]. Xiaojun Bi, Shumin Zhai (2013) "Bayesian Touch - A Statistic Criterion of Target Selection with Finger Touch". In Proceedings of UIST 2013 - The ACM Symposium on User Interface Software and Technology. 51-60 [Acceptance Rate: 20%]

Paper



UIST 2012

[13]. Xiaojun Bi, Ciprian Chelba, Tom Ouyang, Kurt Partridge, Shumin Zhai. (2012) "Bimanual Gesture Keyboard", In Proceedings of UIST 2012 - The ACM Symposium on User Interface Software and Technology. 137-146 [Acceptance Rate 21.5%]

Paper | Video
Mobile interaction research at Google (An article on the Google Research Blog introduces the successful technology transfer)



Human-Computer Interaction 2012, Volume 27

[12]. Xiaojun Bi, Barton A. Smith, Shumin Zhai. (2012) "Multilingual Touchscreen Keyboard Design and Optimization", Human-Computer Interaction, Volume 27, Issue 4, 352-382. [2014 Impact Factor: 3.143]

Author's Accepted Manuscript, Version of Record at Taylor and Francis



CHI 2012

[11]. Ken Hinckley, Xiaojun Bi, Michel Pahud, Bill Buxton. (2012) "Informal Information Gathering Techniques for Active Reading ". In Proceedings of CHI 2012 - the SIGCHI Conference on Human Factors in Computing Systems. 1893-1896. [Acceptance Rate: 23%]

Paper | Video



CHI 2012

[10]. Yizhong Xin, Xiaojun Bi, Xiangshi Ren. (2012) "Natural Use Profiles for the Pen: An Empirical Exploration of Pressure, Tilt, and Azimuth ". In Proceedings of CHI 2012 - the SIGCHI Conference on Human Factors in Computing Systems. 801-804. [Acceptance Rate: 23%].

Paper



CHI 2011

[9]. Xiaojun Bi , Tovi Grossman, Justin Matejka, George Fitzmaurice. (2011) "Magic Desk: Bringing Multi-Touch Surfaces into Desktop Work", In Proceedings of CHI 2011 - the SIGCHI Conference on Human Factors in Computing Systems. 2511-2520. [Acceptance Rate: 26%]

CHI2011 Honorable Mention Award (Top 5%) | Paper | Video



CHI 2011

[8]. Yizhong Xin, Xiaojun Bi , Xiangshi Ren. (2011) "Acquiring and Pointing: An Empirical Study of Pen Tilt-Based Interaction.". In Proceedings of CHI 2011 - the SIGCHI Conference on Human Factors in Computing Systems. 849-858. [Acceptance Rate: 26%].

Paper



CHI 2010

[7]. Xiaojun Bi , Seok-Hyung Bae, Ravin Balakrishnan. (2010) "Effects of Interior Bezels of Tiled-Monitor Large Displays on Visual Search, Tunnel Steering, and Target Selection.". In Proceedings of CHI 2010 - the SIGCHI Conference on Human Factors in Computing Systems. 65-74. [Acceptance Rate: 22%]

Paper



CHI 2010

[6]. Xiaojun Bi, Barton A. Smith, Shumin Zhai. (2010) "Quasi-Qwerty Soft Keyboard Optimization". In Proceedings of CHI 2010 - the SIGCHI Conference on Human Factors in Computing Systems. 283-286. [Acceptance Rate: 22%]

Paper



CHI 2009

[5]. Xiaojun Bi, Ravin Balakrishnan. (2009) "Comparing Usage of a Large High-Resolution Display to Single or Dual Desktop Displays for Daily Work". In Proceedings of CHI 2009 - the SIGCHI Conference on Human Factors in Computing Systems. 1005-1014. [Acceptance Rate: 25%]

Paper



UIST 2008

[4]. Xiaojun Bi, Tomer Moscovich, Gonzalo Ramos, Ravin Balakrishnan, Ken Hinckley. (2008) "An Exploration of Pen Rolling for Pen-based Interaction". In Proceedings of UIST 2008 - The ACM Symposium on User Interface Software and Technology. 191-200. [Acceptance Rate: 18%]

Paper | Video



Mobile HCI 2010

[3]. James Scott, Shahram Izadi, Leila Sadat Rezai, Dominika Ruszkowski, Xiaojun Bi, Ravin Balakrishnan, (2010) "RearType: Text Entry Using Keys on the Back of a Device". In Proceedings of MobileHCI - The ACM Conference on Human computer interaction with Mobile Devices and Services. 171-180. [Acceptance Rate: 23%]

Paper



TableTop 2006

[2]. Xiaojun Bi, Yuanchun Shi, Xiaojie Chen (2006) "uPen: A Smart Pen-liked Device for Facilitating Interaction on Large Displays". In Proceedings of IEEE TableTop Conference on Horizontal Interactive Human-Computer Systems 2006, Australia, January, 160-168.

Paper


EUSAI 2005

[1]. Xiaojun Bi, Yuanchun Shi, Xiaojie Chen, Peifeng Xiang (2005) "Facilitating Interaction with Large Displays in Smart Spaces". In Soc-EUSAI, Smart Objects and Ambient Intelligence Conference. France, October, 2005, 105-110.

Paper


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Workshop Papers

[4]. Xiaojun Bi, Brian A. Smith and Shumin Zhai (2015) Keboard Layout Optimization. In CHI 2015 Workshop on Principles, Techniques and Perspectives on Optimization and HCI..

[3]. Per Ola Kristensson, Xiaojun Bi, Andrew Howes, Antti Oulasvirta, Roderick Murray-Smith, Harold Thimbleby, John Williamson, Shumin Zhai (2015) Principles, Techniques and Perspectives on Optimization and HCI. In CHI EA 2015 - the SIGCHI Conference on Human Factors in Computing Systems. 2441-2444.

[2]. Hao-Chuan Wang, Gary Hsieh, Xiaojun Bi, Henry B. L. Duh, Yihsiu Chen (2015) Chinese CHI Symposium in CHI 2015. In CHI EA 2015 - the SIGCHI Conference on Human Factors in Computing Systems. 2313-2315.

[1]. Shumin Zhai, Xiaojun Bi, Shiri Azenkot, Kurt Partridge (2013) "The Grand Challenge of Automated Evaluation of Text Input Systems". In CHI 2013 Workshop on Grand Challenges in Text Entry.

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Brief Biography

Xiaojun Bi is currently a Human-Computer Interaction research scientist at Google in Mountain View, California. He will join the Department of Computer Science at Stony Brook University as an Assistant Professor in December 2016. His research focuses on building interactive systems, designing interaction techniques, and studying fundamental issues of user interface design especially on mobile devices. He has pioneered a number of techniques for mobile text entry systems, pen and touch based interactive systems, and large display interaction. His recent innovations such as keyboard correction & completion algorithm (CHI 2013) , bimanual gesture typing (UIST 2012), personalizing language models for text entry (CHI 2015) have been integrated into the Android keyboard, used by more than 100 million users. The keyboard evaluation system, Octopus (CHI 2013) has been widely used in the product development. Mobile Interaction Research at Google, a Google Research blog article highlights some of his recent research integrated into the Google products.

Xiaojun Bi has authored over 20 publications in the premier HCI publication venues such as CHI, UIST, and Human Computer Interaction Journal, and 20 US patents (11 issued and 9 pending). His research papers have received awards at CHI, the flagship conference in HCI. His paper studying the speed-accuracy tradeoff of finger touch input (FFitts Law, CHI 2013) won the Google 2013 Influential Paper Award. Xiaojun Bi is active in the HCI academic community. He constantly serves as an Associate Chair on the CHI and UIST program committees, and organizes/co-organizes CHI workshops to prompt research in computational interaction design and text input technology. He is now co-editing the book Computational Interaction Design. He was a program co-chair for Chinese CHI 2015, and now is a general co-chair for Chinese CHI 2016. Xiaojun Bi earned his Ph.D. from the Department of Computer Science at the University of Toronto. He received his Master's and Bachelor's degrees from Tsinghua University. He won the first place in the National Mathematical Olympiad (China) in his home province when he was a high school student, recruited by Tsinghua University with national college entrance examinations waived.

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Research Highlights

Text Entry
The modern computing is moving from a desktop model to a Post-PC, multi-device, information cloud model. Inputting text remains as one of the most important and challenging tasks on non-traditional computing devices (e.g., smart phones and watches). I together with my colleagues have made multiple innovations in this area:
(1) Invented the bimanual gesture typing, which extended the gesture typing paradigm from one to multiple fingers (UIST 2012, Video);
(2) Computationally optimized the keyboard decoding algorithm to improve its correction (i.e., correcting erroneous input) and completion (i.e., completing a word based on partial input) abilities (CHI 2014);
(3) Researched how to personalize language models to improve text entry (CHI 2015);
(4) Implemented a large-scale, and data-driven keyboard evaluation and optimization system (CHI 2013, Video ).

Computational Interface Design
Advances in computational methods and computer engineering have vastly extended the scope of problems that can be solved by a modern computer. However, applying computational methods to solve HCI problems is considerably hard, given the complexity of human behaviors. Fortunately we are able to apply computational methods to solve some well-defined interface design problems. One example is the keyboard layout design. My contributions in this area include:
(1) creating a multilingual layout optimized for input speed of multiple languages including English, French, Spanish, German and Chinese (Human Computer Interaction, 2012);
(2) creating the Quasi-Qwerty layout which is optimized for input speed and learnability (CHI 2011);
(3) optimizing the keyboard layout for gesture typing speed, accuracy and learnability (CHI 2015).

Laws of Action
Establishing robust laws and regularities is fundamental to the development of a research field. This is becoming increasingly important as new input modalieis (e.g., finger touch) and new computing devices (e.g., smart phones, tablets, and watches) are emerging. My research in this area includes:
(1) deriving the Finger-Fitts law (i.e., FFitts law) to specify the speed-accuracy trade-off of finger touch input (CHI 2013);
(2) deriving the Bayesian Touch Criterion, a statistical criterion for ranking target likelihood for target selection tasks (UIST 2013).

Touch and Pen based Interaction
Both finger touch and pen are widely adopted as new input modalities in Post-PC computing. I have built interactive systems with pen and touch as major input modalities, and designed novel pen-based and touch-based interaction techniques. Some major research projects include:
(1) deisgning and implementing interaction techniques on a touch-enabled desk to improve daily desktop computing experience (CHI 2011 | Video);
(2) designing and implementing pen and touch based interaction techniques to support active reading (CHI 2012 | Video )
(3) investigating human's abilities of using pen rolling and tilting as new input modalities, and designing pen rolling and tilting based interaction techniques. (UIST 2008, CHI 2011, CHI 2012).

Large Display Interaction
In addition to the new input modalities, output modalities are becoming diverse in the Post-PC computing, ranging from small-sized screens (e.g., glasses or watches) to wall-sized displays. Challenges arise when users interact with these new modalities. Take the large display as an example. It offers users a large visualization surface and helps users more efficiently process digital information. On the other hand, it imposes challenges because many interfaces were not designed for large surfaces in the first place. I have conduced the following research to address the challenges of using large displays, including:
(1) designing and implementing WallTop, a multi-window based window management system prototype on large displays ( Human Computer Interaction 2014 | Video );
(2) understanding users' behaviors of processing desktop work on large displays (CHI 2009, CHI 2010)

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Patents (11 issued, 9 pending)

  • [P20]. Shumin Zhai, Xiaojun Bi, Yu Ouyang. Incremental multi-touch gesture recognition. US Patent: 9,021,380. Filed: 10/5/2012. Issued: 4/28/2015
  • [P19]. Xiaojun Bi. Keyboard gestures for character string replacement. US Patent: 8,806,384. Filed: 7/2/2014. Issued: 4/14/2015.
  • [P18]. Xiaojun Bi, Kurt Partridge, Yu Ouyang, Shumin Zhai. Character deletion during keyboard gesture. US Patent: 8,914,751. Filed: 1/14/2013. Issued: 12/16/2014
  • [P17]. Xiaojun Bi, Shumin Zhai and Michael Andrew Cleron. Dynamically-positioned character string suggestions for gesture typing. US Patent: 8,887,103. Filed: 1/20/2013. Issued: 11/11/2014
  • [P16]. Xiaojun Bi, Yu Ouyang, Shumin Zhai. Partial gesture text entry. US Patent: 8,850,350. Filed: 10/16/2013. Issued: 9/30/2014
  • [P15]. Yu Ouyang, Shumin Zhai, Xiaojun Bi. Multi-gesture text input prediction. US Patent: 8,843,845. Filed: 4/8/2013. Issued: 9/23/2014
  • [P14]. Xiaojun Bi. Keyboard gestures for character string replacement. US Patent: 8,806,384. Filed: 10/24/2013. Issued: 8/12/2014
  • [P13]. Tom Ouyang, Shumin Zhai, Ciprian Chelba, Xiaojun Bi, Satoshi Kataoka, Ken Wakasa, Keisuke Kuroyanagi. Incremental feature-based gesture-keyboard decoding. US Patent: 8,782,549. Filed: 10/5/2012. Issued: 7/15/2014
  • [P12]. Shumin Zhai, Kurt Partridge, Xiaojun Bi, Tom Ouyang. Visual feedback deletion. US Patent: 8,584,049. Filed: 3/14/2013. Issued: 11/12/2013
  • [P11]. Xiaojun Bi, Barton Smith, Shumin Zhai. Method for optimization of soft keyboards for multiple languages. US Patent: 8,542,195. Filed: 3/30/2010. Issued: 9/24/2013
  • [P10]. Xiaojun Bi, Shumin Zhai. Touchscreen text input. US Patent: 8,405,630. Filed: 04/30/2012. Issued: 3/26/2013.
  • [P9]. Xiaojun Bi. Suggestion selection during continuous gesture input. Application Number: US 14/656,680. Filed: 3/12/2015.
  • [P8]. Xiaojun Bi. Alternative gesture mapping for a graphical keyboard. Application Number: US 14/623,281. Filed: 2/16/2015.
  • [P7]. Xiaojun Bi. Alternative gesture mapping for a graphical keyboard. Application Number: US 62/041,868. Filed: 8/26/2014.
  • [P6]. Xiaojun Bi, Shumin Zhai. Thumb typing keyboard. Application Number: US 14/323,377. Filed: 7/3/2014.
  • [P5]. Xiaojun Bi. Word prediction for numbers and symbols. Application Number: US 14/144,825. Filed: 12/31/2013.
  • [P4]. Xiaojun Bi. Multiple character input with a single selection. Application Number: US 14/102,161. Filed: 12/10/2013.
  • [P3]. Shumin Zhai, Kurt Edward Partridge, Xiaojun Bi, Yu Ouyang. Gesture keyboard with gesture cancellation. Application number: US 13/866,680. Filed: 4/19/2013
  • [P2]. Shumin Zhai, Kurt Edward Partridge, Xiaojun Bi, Yu Ouyang. Contextually-specific automatic separators. Application number: US 13/784,507. Filed: 3/4/2013.
  • [P1]. Tovi Grossman, Justin Frank Matejka,George Fitzmaurice, Xiaojun Bi. Multi-Touch Integrated Desktop Environment. Application number: US 12/985,308. Filed:1/5/2011.
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    Teaching

    TA Positions at the Department of Computer Science, the University of Toronto

    [CSC318] The Design of Interactive Computational Media (2006 Fall)
    [CSC180] Introduction to Computer Programming (2010 Winter, 2008 Fall)
    [CSC108] Introduction to Computer Programming (2010 Winter, 2007 Fall)
    [CSC148] Introduction to Computer Science (2009 Winter, 2007 Winter)

    Supervised/Co-Supervised Students

    Brian Smith , Columbia University, Summer 2014
    Project: Optimizing keyboard layouts for gesture typing (published at CHI 2015 [20]).

    Andrew Fowler, Oregon Health & Science University, Summer 2013 & Spring 2014
    Project: Personalizing language models for touchscreen text entry (published at CHI 2015 [19]).

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    Professional Services

  • Program Committee Member.  ACM Conference on Human Factors in Computing Systems (CHI) 2017, 2016, 2015.
  • Program Committee Member.  ACM Symposium on User Interface Software and Technology (UIST) 2016, 2013.
  • Program Co-chair.  The International Symposium of Chinese CHI 2015.
  • General Co-chair.  The International Symposium of Chinese CHI 2016.
  • Co-organizer.  CHI 2015 Workshop on Principles, Techniques and Perspectives on Optimization and HCI.

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    Last modified 05/30, 2015