Category Archives: cross-device interaction

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]

Paper: Sensing Tablet Grasp + Micro-mobility for Active Reading

Lately I have been thinking about touch:

In the tablet-computer sense of the word.

To most people, this means the touchscreen. The intentional pokes and swipes and pinching gestures we would use to interact with a display.

But not to me.

Touch goes far beyond that.

Look at people’s natural behavior. When they refer to a book, or pass a document to a collaborator, there are two interesting behaviors that characterize the activity.

What I call the seen but unnoticed:

Simple habits and social cues, there all the time, but which fall below our conscious attention — if they are even noticed at all.

By way of example, let’s say we’re observing someone handle a magazine.

First, the person has to grasp the magazine. Seems obvious, but easy to overlook — and perhaps vital to understand. Although grasp typically doesn’t involve contact of the fingers with the touchscreen, this is a form of ‘touch’ nonetheless, even if it is one that traditionally hasn’t been sensed by computers.

Grasp reveals a lot about the intended use, whether the person might be preparing to pick up the magazine or pass it off, or perhaps settling down for a deep and immersive engagement with the material.

Second, as an inevitable consequence of grasping the magazine, it must move. Again, at first blush this seems obvious. But these movements may be overt, or they may be quite subtle. And to a keen eye — or an astute sensing system — they are a natural consequence of grasp, and indeed are what give grasp its meaning.

In this way, sensing grasp informs the detection of movements.

And, coming full circle, the movements thus detected enrich what we can glean from grasp as well.

Yet, this interplay of grasp and movement has rarely been recognized, much less actively sensed and used to enrich and inform interaction with tablet computers.

And this feeds back into a larger point that I have often found myself trying to make lately, namely that touch is about far more than interaction with the touch-screen alone.

If we want to really understand touch (as well as its future as a technology) then we need to deeply understand these other modalities — grasp and movement, and perhaps many more — and thereby draw out the full naturalness and expressivity of interaction with tablets (and mobile phones, and e-readers, and wearables, and many dreamed-of form-factors perhaps yet to come).

My latest publication looks into all of these questions, particularly as they pertain to reading electronic documents on tablets.

We constructed a tablet (albeit a green metallic beast of one at present) that can detect natural grips along its edges and on the entire back surface of the device. And with a full complement of inertial motion sensors, as well. This image shows the grip-sensing (back) side of our technological monstrosity:

Grip Sensing Tablet Hardware

But this set-up allowed us to explore ways of combining grip and subtle motion (what has sometimes been termed micro-mobility in the literature), resulting in the following techniques (among a number of others):

A Single User ENGAGING with a Single Device

Some of these techniques address the experience of an individual engaging with their own reading material.

For example, you can hold a bookmark with your thumb (much as you can keep your finger on a page in physical book) and then tip the device. This flips back to the page that you’re holding:


This ‘Tip-to-Flip’ interaction  involves both the grip and the movement of the device and results in a fairly natural interaction that builds on a familiar habit from everyday experience with physical documents.

Another one we experimented with was a very subtle interaction that mimics holding a document and angling it up to inspect it more closely. When we sense this, the tablet zooms in slightly on the page, while removing all peripheral distractions such as menu-bars and icons:

Immersive Reading mode through grip sensing

This immerses the reader in the content, rather than the iconographic gewgaws which typically border the screen of an application as if to announce, “This is a computer!”

Multiple Users Collaborating around a Single Device

Another set of techniques we explored looked at how people pass devices to one another.

In everyday experience, passing a paper document to a collaborator is a very natural — and different — form of “sharing,” as compared to the oft-frustrating electronic equivalents we have at our disposal.

Likewise, computers should be able to sense and recognize such gestures in the real world, and use them to bring some of the socially and situationally appropriate sharing that they afford to the world of electronic documents.

We explored one such technique that automatically sets up a guest profile when you hand a tablet (displaying a specific document) to another user:


The other user can then read and mark-up that document, but he is not the beneficiary of a permanent electronic copy of it (as would be the case if you emailed him an attachment), nor is he permitted to navigate to other areas or look at other files on your tablet.

You’ve physically passed him the electronic document, and all he can do is look at it and mark it up with a pen.

Not unlike the semantics — long absent and sorely missed in computing — of a simple a piece of paper.

A Single User Working With Multiple Devices

A final area we looked at considers what happens when people work across multiple tablets.

We already live in a world where people own and use multiple devices, often side-by-side, yet our devices typically have little or no awareness of one another.

But contrast this to the messy state of people’s physical desks, with documents strewn all over. People often place documents side-by-side as a lightweight and informal way of organization, and might dexterously pick one up or hold it at the ready for quick reference when engaged in an intellectually demanding task.

Again, missing from the world of the tablet computer.

But by sensing which tablets you hold, or pick up, our system allows people to quickly refer to and cross-reference content across federations of such devices.

While the “Internet of Things” may be all the rage these days among the avant-garde of computing, such federations remain uncommon and in our view represent the future of a ‘Society of Devices’ that can recognize and interact with one another, all while respecting social mores, not the least of which are the subtle “seen but unnoticed” social cues afforded by grasping, moving, and orienting our devices.


Closing ThoughtS:

An ExpanDED Perspective OF ‘TOUCH’

The examples above represent just a few simple steps. Much more can, and should, be done to fully explore and vet these directions.

But by viewing touch as far more than simple contact of the fingers with a grubby touchscreen — and expanding our view to consider grasp, movement of the device, and perhaps other qualities of the interaction that could be sensed in the future as well — our work hints at a far wider perspective.

A perspective teeming with the possibilities that would be raised by a society of mobile appliances with rich sensing capabilities, potentially leading us to far more natural, more expressive, and more creative ways of engaging in the knowledge work of the future.



Sensing-Tablet-Grasp-Micro-Mobility-UIST-2015-thumbDongwook Yoon, Ken Hinckley, Hrvoje Benko, François Guimbretière, Pourang Irani, Michel Pahud, and Marcel Gavriliu. 2015. Sensing Tablet Grasp + Micro-mobility for Active Reading. In Proceedings of the 28th Annual ACM Symposium on User Interface Software & Technology (UIST ’15). ACM, New York, NY, USA, 477-487. Charlotte, NC, Nov. 8-11, 2015.
[PDF] [Talk slides PPTX] [video – MP4] [30 second preview – MP4] [Watch on YouTube]

Watch Sensing Tablet Grasp + Micro-mobility for Active Reading video 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: 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

Paper: Cross-Device Interaction via Micro-mobility and F-formations (“GroupTogether”)

GroupTogetherMarquardt, N., Hinckley, K., and Greenberg, S., Cross-Device Interaction via Micro-mobility and F-formations.  In ACM UIST 2012 Symposium on User Interface Software and Technology (UIST ’12). ACM, New York, NY, USA,  Cambridge, MA, Oct. 7-10, 2012, pp. (TBA). [PDF] [video – WMV]. Known as the GroupTogether system.

See also my post with some further perspective on the GroupTogether project.

Watch the GroupTogether video on YouTube

Paper: CodeSpace: Touch + Air Gesture Hybrid Interactions for Supporting Developer Meetings

CodeSpace systemBragdon, A., DeLine, R., Hinckley, K., and Morris, M. R., Code space: Touch + Air Gesture Hybrid Interactions for Supporting Developer Meetings.  In Proc. ACM International Conference on Interactive Tabletops and Surfaces (ITS ’11). ACM, New York, NY, USA,  Kobe, Japan, November 13-16, 2011, pp. 212-221. [PDF] [video – WMV]. As featured on Engadget and many other online forums.

Watch CodeSpace video on YouTube

Book Chapter: Input Technologies and Techniques, 2012 Edition

Input Technologies and Techniques, 3rd EditionHinckley, K., Wigdor, D., Input Technologies and Techniques. Chapter 9 in The Human-Computer Interaction Handbook – Fundamentals, Evolving Technologies and Emerging Applications, Third Edition, ed. by Jacko, J., Published by Taylor & Francis. To appear. [PDF of author’s manuscript – not final]

This is an extensive revision of the 2007 and 2002 editions of my book chapter, and with some heavy weight-lifting from my new co-author Daniel Wigdor, it treats direct-touch input devices and techniques in much more depth. Lots of great new stuff. The book will be out in early 2012 or so from Taylor & Francis – keep an eye out for it!