Category Archives: Ubiquitous Computing

ACM SIGMOBILE 2017 Test of Time Award for “Sensing Techniques for Mobile Interaction”

Recently the SIGMOBILE community recognized my turn-of-the-century research on mobile sensing techniques with one of their 2017 Test of Time Awards.

This was the paper (“Sensing Techniques for Mobile Interaction“) that first introduced techniques such as automatic screen rotation and raise-to-wake to mobile computing — features now taken for granted on the iPhones and tablets of the world.

The award committee motivated the award as follows:

This paper showed how combinations of simple sensors could be used to create rich mobile interactions that are now commonplace in mobile devices today. It also opened up people’s imaginations about how we could interact with mobile devices in the future, inspiring a wide range of research on sensor-based interaction techniques.


And so as not to miss the opportunity to have fun with the occasion, in the following video I reflected (at times irreverently) on the work — including  what I really thought about it at the time I was doing the research.

And some of the things that still surprise me about it after all these years.

You can find the original paper here.

Thumbnail - Ken Hinckley CHI Academy 2014 InducteeHinckley, K., Pierce, J., Sinclair, M., Horvitz, E. ACM SIGMOBILE 2017 Test of Time Award. [SIGMOBILE Test of Time Awards archive]

Paper: WritLarge: Ink Unleashed by Unified Scope, Action, & Zoom

Electronic whiteboards remain surprisingly difficult to use in the context of creativity support and design.

A key problem is that once a designer places strokes and reference images on a canvas, actually doing anything useful with key parts of that content involves numerous steps.

Hence, with digital ink, scope—that is, selection of content—is a central concern, yet current approaches often require encircling ink with a lengthy lasso, if not switching modes via round-trips to the far-off edges of the display.

Only then can the user take action, such as to copy, refine, or re-interpret their informal work-in-progress.

Such is the stilted nature of selection and action in the digital world.

But it need not be so.

By contrast, consider an everyday manual task such as sandpapering a piece of woodwork to hew off its rough edges. Here, we use our hands to grasp and bring to the fore—that is, select—the portion of the work-object—the wood—that we want to refine.

And because we are working with a tool—the sandpaper—the hand employed for this ‘selection’ sub-task is typically the non-preferred one, which skillfully manipulates the frame-of-reference for the subsequent ‘action’ of sanding, a complementary sub-task articulated by the preferred hand.

Therefore, in contrast to the disjoint subtasks foisted on us by most interactions with computers, the above example shows how complementary manual activities lend a sense of flow that “chunks” selection and action into a continuous selection-action phrase. By manipulating the workspace, the off-hand shifts the context of the actions to be applied, while the preferred hand brings different tools to bear—such as sandpaper, file, or chisel—as necessary.

The main goal of the WritLarge project, then, is to demonstrate similar continuity of action for electronic whiteboards. This motivated free-flowing, close-at-hand techniques to afford unification of selection and action via bimanual pen+touch interaction.


Accordingly, we designed WritLarge so that user can simply gesture as follows:

With the thumb and forefinger of the non-preferred hand, just frame a portion of the canvas.

And, unlike many other approaches to “handwriting recognition,” this approach to selecting key portions of an electronic whiteboard leaves the user in complete control of what gets recognized—as well as when recognition occurs—so as not to break the flow of creative work.

Indeed, building on this foundation, we designed ways to shift between flexible representations of freeform content by simply moving the pen along semantic, structural, and temporal axes of movement.

See our demo reel below for some jaw-dropping demonstrations of the possibilities for digital ink opened up by this approach.

Watch WritLarge: Ink Unleashed by Unified Scope, Action, and Zoom video on YouTube

WritLarge-CHI-2017-thumbHaijun Xia, Ken Hinckley, Michel Pahud, Xioa Tu, and Bill Buxton. 2017. WritLarge: Ink Unleashed by Unified Scope, Action, and Zoom. In Proceedings of the 2017 CHI Conference on Human Factors in Computing Systems (CHI’17). ACM, New York, NY, USA, pp. 3227-3240. Denver, Colorado, United States, May 6-11, 2017. Honorable Mention Award (top 5% of papers).

[PDF] [Watch 30 second preview on YouTube]

Paper: As We May Ink? Learning from Everyday Analog Pen Use to Improve Digital Ink Experiences

This work sheds light on gaps and discrepancies between the experiences afforded by analog pens and their digital counterparts.

Despite the long history (and recent renaissance) of digital pens, the literature still lacks a comprehensive survey of what types of marks people make and what motivates them to use ink—both analog and digital—in daily life.


To capture the diversity of inking behaviors and tease out the unique affordances of pen-and ink, we conducted a diary study with 26 participants from diverse backgrounds.

From analysis of 493 diary entries we identified 8 analog pen-and-ink activities, and 9 affordances of pens. We contextualized and contrasted these findings using a survey with 1,633 respondents and a follow-up diary study with 30 participants, observing digital pens.

Our analysis revealed many gaps and research opportunities based on pen affordances not yet fully explored in the literature.

As-We-May-Ink-CHI-2017-thumbYann Riche, Nathalie Henry Rich, Ken Hinckley, Sarah Fuelling, Sarah Williams, and Sheri Panabaker. 2017. As We May Ink? Learning from Everyday Analog Pen Use to Improve Digital Ink Experiences. In Proceedings of the 2017 CHI Conference on Human Factors in Computing Systems (CHI’17). ACM, New York, NY, USA, pp. 3241-3253. Denver, Colorado, United States, May 6-11, 2017.

[PDF] [CHI 2017 Talk Slides (PowerPoint)]

Paper: Wearables as Context for Guiard-abiding Bimanual Touch

This particular paper has a rather academic-sounding title, but at its heart it makes a very simple and interesting observation regarding touch that any user of touch-screen technology can perhaps appreciate.

The irony is this: when interaction designers talk about “natural” interaction, they often have touch input in mind. And so people tend to take that for granted. What could be simpler than placing a finger — or with the modern miracle of multi-touch, multiple fingers — on a display?

And indeed, an entire industry of devices and form-factors — everything from phones, tablets, drafting-tables, all the way up to large wall displays — has arisen from this assumption.

Yet, if we unpack “touch” as it’s currently realized on most touchscreens, we can see that it remains very much a poor man’s version of natural human touch.

For example, on a large electronic-whiteboard such as the 84″ Surface Hub, multiple people can work upon the display at the same time. And it feels natural to employ both hands — as one often does in a wide assortment of everyday manual activities, such as indicating a point on a whiteboard with your off-hand as you emphasize the same point with the marker (or electronic pen).

Yet much of this richness — obvious to anyone observing a colleague at a whiteboard — represents context that is completely lost with “touch” as manifest in the vast majority of existing touch-screen devices.

For example:

  • Who is touching the display?
  • Are they touching the display with one hand, or two?
  • And if two hands, which of the multiple touch-events generated come from the right hand, and which come from the left?

Well, when dealing with input to computers, the all-too-common answer from the interaction designer is a shrug, a mumbled “who the heck knows,” and a litany of assumptions built into the user interface to try and paper over the resulting ambiguities, especially when the two factors (which user, and which hand) compound one another.

The result is that such issues tend to get swept under the rug, and hardly anybody ever mentions them.

But the first step towards a solution is recognizing that we have a problem.

This paper explores the implications of one particular solution that we have prototyped, namely leveraging wearable devices on the user’s body as sensors that can augment the richness of touch events.

A fitness band worn on the non-preferred hand, for example, can sense the impulse resulting from making finger-contact with a display through its embedded motion sensors (accelerometers and gyros). If the fitness band and the display exchange information and id’s, the touch-event generated can then be associated with the left hand of a particular user. The inputs of multiple users instrumented in this manner can then be separated from one another, as well, and used as a lightweight form of authentication.

That then explains the “wearable” part of “Wearables as Context for Guiard-abiding Bimanual Touch,” the title of my most recent paper, but what the heck does “Guiard-abiding” mean?

Well, this is a reference to classic work by a research colleague, Yves Guiard, who is famous for a 1987 paper in which he made a number of key observations regarding how people use their hands — both of them — in everyday manual tasks.

Particularly, in a skilled manipulative task such as writing on a piece of paper, Yves pointed out (assuming a right-handed individual) three general principles:

  • Left hand precedence: The action of the left hand precedes the action of the right; the non-preferred hand first positions and orients the piece of paper, and only then does the pen (held in the preferred hand, of course) begin to write.
  • Differentiation in scale: The action of the left hand tends to occur at a larger temporal and spatial scale of motion; the positioning (and re-positioning) of the paper tends to be infrequent and relatively coarse compared to the high-frequency, precise motions of the pen in the preferred hand.
  • Right-to-Left Spatial Reference: The left hand sets a frame of reference for the action of the right; the left hand defines the position and orientation of the work-space into which the preferred hand inserts its contributions, in this example via the manipulation of a hand-held implement — the pen.

Well, as it turns out these three principles are very deep and general, and they can yield great insight into how to design interactions that fully take advantage of people’s everyday skills for two-handed (“bimanual”) manipulation — another aspect of “touch” that interaction designers have yet to fully leverage for natural interaction with computers.

This paper is a long way from a complete solution to the paucity of modern touch-screens but hopefully by pointing out the problem and illustrating some consequences of augmenting touch with additional context (whether provided through wearables or other means), this work can lead to more truly “natural” touch interaction — allowing for simultaneous interaction by multiple users, both of whom can make full and complementary use of their hard-won manual skill with both hands — in the near future.

Wearables (fitness band and ring) provide missing context (who touches, and with what hand) for direct-touch bimanual interactions.Andrew M. Webb, Michel Pahud, Ken Hinckley, and Bill Buxton. 2016. Wearables as Context for Guiard-abiding Bimanual Touch. In Proceedings of the 29th Annual ACM Symposium on User Interface Software and Technology (UIST ’16). ACM, New York, NY, USA, 287-300. Tokyo, Japan, Oct. 16-19, 2016.
[PDF] [Talk slides PDF] [Full video – MP4] [Watch 30 second preview on YouTube]

Book Chapter: Input/Output Devices and Interaction Techniques, Third Edition

Thumbnail for Computing Handbook (3rd Edition)Hinckley, K., Jacob, R., Ware, C. Wobbrock, J., and Wigdor, D., Input/Output Devices and Interaction Techniques. Appears as Chapter 21 in The Computing Handbook, Third Edition: Two-Volume Set, ed. by Tucker, A., Gonzalez, T., Topi, H., and Diaz-Herrera, J. Published by Chapman and Hall/CRC (Taylor & Francis), May 13, 2014.  [PDF – Author’s Draft – may contain discrepancies]

Paper: LightRing: Always-Available 2D Input on Any Surface

In this modern world bristling with on-the-go-go-go mobile activity, the dream of an always-available pointing device has long been held as a sort of holy grail of ubiquitous computing.

Ubiquitous computing, as futurists use the term, refers to the once-farfetched vision where computing pervades everything, everywhere, in a sort of all-encompassing computational nirvana of socially-aware displays and sensors that can respond to our every whim and need.

From our shiny little phones.

To our dull beige desktop computers.

To the vast wall-spanning electronic whiteboards of a future largely yet to come.

How will we interact with all of these devices as we move about the daily routine of this rapidly approaching future? As we encounter computing in all its many forms, carried on our person as well as enmeshed in the digitally enhanced architecture of walls, desktops, and surfaces all around?

Enter LightRing, our early take on one possible future for ubiquitous interaction.

LightRing device on a supporting surface

By virtue of being a ring always worn on the finger, LightRing travels with us and is always present.

By virtue of some simple sensing and clever signal processing, LightRing can be supported in an extremely compact form-factor while providing a straightforward pointing modality for interacting with devices.

At present, we primarily consider LightRing as it would be configured to interact with a situated display, such as a desktop computer, or a presentation projected against a wall at some distance.

The user moves their index finger, angling left and right, or flexing up and down by bending at the knuckle. Simple stuff, I know.

But unlike a mouse, it’s not anchored to any particular computer.

It travels with you.

It’s a go-everywhere interaction modality.

Close-up of LightRing and hand angles inferred from sensors

Left: The degrees-of-freedom detected by the LightRing sensors. Right: Conceptual mapping of hand movement to the sensed degrees of freedom. LightRing then combines these to support 2D pointing at targets on a display, or other interactions.

LightRing can then sense these finger movements–using a one-dimensional gyroscope to capture the left-right movement, and an infrared sensor-emitter pair to capture the proximity of the flexing finger joint–to support a cursor-control mode that is similar to how you would hold and move a mouse on a desktop.

Except there’s no mouse at all.

And there needn’t even be a desktop, as you can see in the video embedded below.

LightRing just senses the movement of your finger.  You can make the pointing motions on a tabletop, sure, but you can just as easily do them on a wall. Or on your pocket. Or a handheld clipboard.

All the sensing is relative so LightRing always knows how to interpret your motions to control a 2D cursor on a display. Once the LightRing has been paired with a situated device, this lets you point at targets, even if the display itself is beyond your physical reach. You can sketch or handwrite characters with your finger–another scenario we have explored in depth on smartphones and even watches.

The trick to the LightRing is that it can automatically, and very naturally, calibrate itself to your finger’s range of motion if you just swirl your finger. From that circular motion LightRing can work backwards from the sensor values to how your finger is moving, assuming it is constrained to (roughly) a 2D plane. And that, combined with a button-press or finger touch on the ring itself, is enough to provide an effective input device.

The LightRing, as we have prototyped it now, is just one early step in the process. There’s a lot more we could do with this device, and many more practical problems that would need to be resolved to make it a useful adjunct to everyday devices–and to tap its full potential.

But my co-author Wolf Kienzle and I are working on it.

And hopefully, before too much longer now, we’ll have further updates on even more clever and fanciful stuff that we can do through this one tiny keyhole into this field of dreams, the verdant golden country of ubiquitous computing.


LightRing thumbnailKienzle, W., Hinckley, K., LightRing: Always-Available 2D Input on Any Surface. In the 27th ACM Symposium on User Interface Software and Technology (UIST 2014), Honolulu, Hawaii, Oct. 5-8, 2014, pp. 157-160. [PDF] [video.mp4 TBA] [Watch on YouTube]

Watch LightRing video on YouTube

Paper: Gradual Engagement between Digital Devices as a Function of Proximity: From Awareness to Progressive Reveal to Information Transfer

I collaborated on a nifty project with the fine folks from Saul Greenberg’s group at the University of Calgary exploring the emerging possibilities for devices to sense and respond to their digital ecology. When devices have fine-grained sensing of their spatial relationships to one another, as well as to the people in that space, it brings about new ways for users to interact with the resulting system of cooperating devices and displays.

This fine-grained sensing approach makes for an interesting contrast to what Nic Marquardt and I explored in GroupTogether, which intentionally took a more conservative approach towards the sensing infrastructure — with the idea in mind that sometimes, one can still do a lot with very little (sensing).

Taken together, the two papers nicely bracket some possibilities for the future of cross-device interactions and intelligent environments.

This work really underscores that we are still largely in the dark ages with regard to such possibilities for digital ecologies. As new sensors and sensing systems make this kind of rich awareness of the surround of devices and users possible, our devices, operating systems, and user experiences will grow to encompass the expanded horizons of these new possibilities as well.

The full citation and the link to our scientific paper are as follows:

Gradual Engagement with devices via proximity sensingMarquardt, N., Ballendat, T., Boring, S., Greenberg, S. and Hinckley, K., Gradual Engagement between Digital Devices as a Function of Proximity: From Awareness to Progressive Reveal to Information Transfer. In Proceedings of ACM Interactive Tabletops & Surfaces (ITS 2012). Boston, MA, USA, November 11-14. 10pp. [PDF] [video – MP4].

Watch the Gradual Engagement via Proximity video on YouTube