Paper: The “Seen but Unnoticed” Vocabulary of Natural Touch: Revolutionizing Direct Interaction with Our Devices and One Another

In this Vision (for the UIST 2021 Symposium on User Interface Software & Technology), I argue that “touch” input and interaction remains in its infancy when viewed in context of the seen but unnoticed vocabulary of natural human behaviors, activity, and environments that surround direct interaction with displays.

Unlike status-quo touch interaction — a shadowplay of fingers on a single screen — I argue that our perspective of direct interaction should encompass the full rich context of individual use (whether via touch, sensors, or in combination with other modalities), as well as collaborative activity where people are engaged in local (co-located), remote (tele-present), and hybrid work.

We can further view touch through the lens of the “Society of Devices,” where each person’s activities span many complementary, oft-distinct devices that offer the right task affordance (input modality, screen size, aspect ratio, or simply a distinct surface with dedicated purpose) at the right place and time.

While many hints of this vision already exist in the literature, I speculate that a comprehensive program of research to systematically inventory, sense, and design interactions around such human behaviors and activities—and that fully embrace touch as a multi-modal, multi-sensor, multi-user, and multi-device construct—could revolutionize both individual and collaborative interaction with technology.

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For the remote presentation, instead of a normal academic talk, I recruited my friend and colleague Nicolai Marquardt to have a 15-minute conversation with me about the vision and some of its implications:

Watch the “Seen but Unnoticed” UIST 2021 Vision presentation video on YouTube

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Several aspects of this vision paper relate to a larger Microsoft Research project known as SurfaceFleet that explores the distributed systems and user experience implications of a “Society of Devices” in the New Future of Work.

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Ken Hinckley. The “Seen but Unnoticed” Vocabulary of Natural Touch: Revolutionizing Direct Interaction with Our Devices and One Another. UIST Vision presented at The 34th Annual ACM Symposium on User Interface Software and Technology (UIST ’21). Non-archival publication, 5 pages. Virtual Event, USA, Oct 10-14, 2021.
https://arxiv.org/abs/2310.03958

[PDF] [captioned presentation video – mp4]

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

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Haijun 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).
https://doi.org/10.1145/3025453.3025664

[PDF] [30 second preview – mp4 | YouTube] [Full video – mp4]

Paper: Thumb + Pen Interaction on Tablets

Modern tablets support simultaneous pen and touch input, but it remains unclear how to best leverage this capability for bimanual input when the nonpreferred hand holds the tablet.

We explore Thumb + Pen interactions that support simultaneous pen and touch interaction, with both hands, in such situations. Our approach engages the thumb of the device-holding hand, such that the thumb interacts with the touch screen in an indirect manner, thereby complementing the direct input provided by the preferred hand.

For instance, the thumb can determine how pen actions (articulated with the opposite hand) are interpreted.

Alternatively, the pen can point at an object, while the thumb manipulates one or more of its parameters through indirect touch.

Our techniques integrate concepts in a novel way that derive from radial menus (also known as marking menus) and spring-loaded modes maintained by muscular tension — as well as indirect input, and in ways that leverage multi-touch conventions.

Our overall approach takes the form of a set of probes, each representing a meaningfully distinct class of application. They serve as an initial exploration of the design space at a level which will help determine the feasibility of supporting bimanual interaction in such contexts, and the viability of the Thumb + Pen techniques in so doing.

Watch Thumb + Pen Interaction on Tablets video on YouTube

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Ken Pfeuffer, Ken Hinckley, Michel Pahud, and Bill Buxton. 2017. Thumb + Pen Interaction on Tablets. In Proceedings of the 2017 CHI Conference on Human Factors in Computing Systems (CHI’17). ACM, New York, NY, USA, pp. 3254-3266 . Denver, Colorado, United States, May 6-11, 2017.
https://doi.org/10.1145/3025453.3025567

[PDF] [30s preview – mp4 | YouTube] [Full video – mp4]

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.

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Yann 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.
https://doi.org/10.1145/3025453.3025716

[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.

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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. https://doi.org/10.1145/2984511.2984564
[PDF] [Talk slides PDF] [30 second preview on YouTube] [Full video – MP4]

Book Chapter: Inking Outside the Box — How Context Sensing Affords More Natural Pen (and Touch) Computing

“Pen” and “Touch” are terms that tend to be taken for granted these days in the context of interaction with mobiles, tablets, and electronic-whiteboards alike.

Yet, as I have discussed in many articles here, even in the simplest combination of these modalities — that of “Pen + Touch” — new opportunities for interaction design abound.

And from this perspective we can go much further still.

Take “touch,” for example.

What does this term really mean in the context of input to computers?

Is it just when the user intentionally moves a finger into contact with the screen?

What if the palm accidentally brushes the display instead — is that still “touch?”

Or how about the off-hand, which plays a critical but oft-unnoticed role in gripping and skillfully orienting the device for the action of the preferred hand? Isn’t that an important part of “touch” as well?

Well, there’s good reason to argue that from the human perspective, these are all “touch,” even though most existing devices only generate a touch-event at the moment when a finger comes into contact with the screen.

Clearly, this is a very limited view, and clearly with greater insight of the context surrounding a particular touch (or pen, or pen + touch) event, we could enhance the naturalness of working with computers considerably.

This chapter, then, works through a series of examples and perspectives which demonstrate how much richness there is in such a re-conception of direct interaction with computers, and thereby suggests some directions for future innovations and richer, far more expressive interactions.

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Hinckley, Ken, and Buxton, Bill. Inking Outside the Box: How Context Sensing Affords More Natural Pen (and Touch) Computing. Appears as Chapter 3 in Revolutionizing Education with Digital Ink: The Impact of Pen and Touch Technology on Education (Human-Computer Interaction Series), First Edition (2016). Ed. by Tracy Hammond, Stephanie Valentine, & Aaron Adler. Published by Springer, Cham. June 13, 2016. https://doi.org/10.1007/978-3-319-31193-7_3

[PDF – Author’s draft]

P.S.: I’ve linked to the draft of the chapter that I submitted to the publisher, rather than the final version, as the published copy-edit muddied the writing by a gross misapplication of the Chicago Manual of Style, and in so doing introduced many semantic errors as well. Despite my best efforts I was not able to convince the publisher to fully reverse these undesired and unfortunate “improvements.” As such, my draft may contain some typographical errors or other minor discrepancies from the published version, but it is the authoritative version as far as I am concerned.

Paper: Pre-Touch Sensing for Mobile Interaction

I have to admit it: I feel as if I’m looking at the sunrise of what may be a whole new way of interacting with mobile devices.

When I think about it, the possibilities bathe my eyes in a golden glow, and the warmth drums against my skin.

And in particular, my latest research peers out across this vivid horizon, to where I see touch — and mobile interaction with touchscreens in particular — evolving in the near future.

As a seasoned researcher, my job (which in reality is some strange admixture of interaction design, innovator, and futurist) is not necessarily to predict the future, but rather to invent it via extrapolation from a sort of visionary present which occupies my waking dreams.

I see things not as they are, but as they could be, through the lens afforded by a (usually optimistic) extrapolation from extant technologies, or those I know are likely to soon become more widely available.

With regards to interaction with touchscreens in particular, it has been clear to me for some time that the ability to sense the fingers as they approach the device — well before contact with the screen itself — is destined to become commonplace on commodity devices.

This is interesting for a number of reasons.

And no, the ability to do goofy gestures above the screen, waving at it frantically (as if it were a fancy-pants towel dispenser in a public restroom) in some dim hope of receiving an affirmative response, is not one of them.

In terms of human capabilities, one obviously cannot touch the screen of a mobile device without approaching it first.

But what often goes unrecognized is that one also must hold the device, typically in the non-preferred hand, as a precursor to touch. Hence, how you hold the device — the pattern of your grip and which hand you hold it in — are additional details of context that are more-or-less wholly ignored by current mobile devices.

So in this new work, my colleagues and I collectively refer to these two precursors of touch — approach and the need to grip the device — as pre-touch.

And it is my staunch belief that the ability to sense such pre-touch information could radically transform the mobile ‘touch’ interfaces that we all have come to take for granted.

You can get a sense of these possibilities, all implemented on a fully functional mobile phone with pre-touch sensing capability, in our demo reel below:

The project received a lot of attention, and coverage from many of the major tech blogs and other media outlets, for example:

• The Verge (“Microsoft’s hover gestures for Windows phones are magnificent”)
• SlashGear (“Smartphones next big thing: ‘Pre-Touch’”)
• Business Insider (“Apple should definitely copy Microsoft’s incredible finger-sensing smartphone technology”)
• And Fast Company Design (and again in “8 Incredible Prototypes That Show The Future Of Human-Computer Interaction.”) (paywalled)

But I rather liked the take that Silicon Angle offered, which took my concluding statement from the video above:

Taken as a whole, our exploration of pre-touch hints that the evolution of mobile touch may still be in its infancy – with many possibilities, unbounded by the flatland of the touchscreen, yet to explore.

 And then responded as follows:

This is the moon-landing-esque conclusion Microsoft comes to after demonstrating its rather cool pre-touch mobile technology, i.e., a mobile phone that senses what your fingers are about to do.

While this evolution of touch has been coming in the research literature for at least a decade now, what exactly to do with above- and around-screen sensing (especially in a mobile setting) has been far from obvious. And that’s where I think our work on pre-touch sensing techniques for mobile interaction distinguishes itself, and in so doing identifies some very interesting use cases that have never been realized before.

The very best of these new techniques possess a quality that I love, namely that they have a certain surprising obviousness to them:

The techniques seem obvious — but only in retrospect.

And only after you’ve been surprised by the new idea or insight that lurks behind them.

If such an effort is indeed the first hint of a moonshot for touch, well, that’s a legacy for this project that I can live with.

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UPDATE: The talk I gave at the CHI 2016 conference on this project is now available. Have a gander if you are so inclined.

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Ken Hinckley, Seongkook Heo, Michel Pahud, Christian Holz, Hrvoje Benko, Abigail Sellen, Richard Banks, Kenton O’Hara, Gavin Smyth, William Buxton. 2016. Pre-Touch Sensing for Mobile Interaction. In Proceedings of the 2016 CHI Conference on Human Factors in Computing Systems (CHI ’16). ACM, New York, NY, USA, p. 2869-2881. San Jose, CA, May 7-12, 2016. http://dx.doi.org/10.1145/2858036.2858095

[PDF] [Talk slides PPTX] [video – MP4] [30 second preview – MP4] [Watch on YouTube]

Watch Pre-Touch Sensing for Mobile Interaction video on YouTube

Olfactory Pen Creates Giant Stink, Fails to Make it out of Research Skunkworks

Microsoft has shown incredible stuff this week at \\build around Pen and Ink experiences — including simultaneous Pen + Touch experiences — as showcased for example in the great video on “Inking at the Speed of Thought” that is now available on Channel 9.

But I’ve had a skunkworks project — so to speak — in the works as part of my research (in the course of a career spanning decades) for a long time now, and this particular vision of the future of pen computing has consumed my imagination for at least the last 37 seconds or so. I’ve put a lot of thought into it.

It’s long been recognized that the sense of smell is a powerful index into the human memory. The scent of decaying pulp instantly brings to mind a favorite book, for example — in my case a volume of the masterworks of Edgar Allen Poe that was bequeathed to me by my grandfather.

Or who can ever forget the dizzying scent of their first significant other?

So I thought: Why not a digital pen with olfactory output?

Just think of the possibilities for this remarkable technology:

Not only can you ink faster than the speed of thought, but now you can stink faster than the speed of thought!

And I’m here to tell you that this is entirely possible. I think. I’ve already conceived of an amazing confabulation called the Aromatic Recombinator (patent pending; filed April 1st, 2016 at 2:55 PM; summarily rejected by patent office, 2:57 PM; earnest appeal filed in hope of an affirmative response, 2:59 PM; earnest response received: TBA).

Nonetheless, I can understand the patent office’s reticence.

Because with this remarkable technology one can arouse almost any scent, from the headiest of perfumes all the way to the most cloying musk, simply by scribbling on the screen of your tablet as if it were an electronic scratch-n-sniff card. A conception on which I have another patent pending, by the way.

Admittedly, some details remain sketchy, but I remain highly optimistic that the obvious problems can be sniffed out in short order.

And if not, rest assured, I will raise one hell of a stink.

[Happy April Fools Day.]

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:

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

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:

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:

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.

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Dongwook 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. http://dx.doi.org/10.1145/2807442.2807510
[PDF] [Talk slides – PowerPoint] [30 second preview – mp4] [Full video – mp4 | YouTube]

Paper: Sensing Techniques for Tablet+Stylus Interaction (Best Paper Award)

It’s been a busy year, so I’ve been more than a little remiss in posting my Best Paper Award recipient from last year’s User Interface Software & Technology (UIST) symposium.

UIST is a great venue, particularly renowned for publishing cutting-edge innovations in devices, sensors, and hardware.

And software that makes clever uses thereof.

Title slide from my talk on this project. We had a lot of help, fortunately. The picture illustrates a typical scenario in pen & tablet interaction — where the user interacts with touch, but the pen is still at the ready, in this case palmed in the user’s fist.

The paper takes two long-standing research themes for me — pen (plus touch) interaction, and interesting new ways to use sensors — and smashes them together to produce the ultimate Frankenstein child of tablet computing:

Microsoft Research’s sensor pen. It’s covered in groovy orange shrink-wrap, too. What could be better than that? (The shrink wrap proved necessary to protect some delicate connections between our grip sensor and the embedded circuitry).

And if you were to unpack this orange-gauntleted beast, here’s what you’d find:

Components of the sensor pen, including inertial sensors, a AAAA battery, a Wacom mini pen, and a flexible capacitive substrate that wraps around the barrel of the pen.

But although the end-goal of the project is to explore the new possibilities afforded by sensor technology, in many ways, this paper kneads a well-worn old worry bead for me.

It’s all about the hand.

With little risk of exaggeration you could say that I’ve spent decades studying nothing but the hand. And how the hand is the window to your mind… [Spark radio interview with Ken Hinckley]

Or shall I say hands. How people coordinate their action. How people manipulate objects. How people hold things. How we engage with the world through the haptic sense, how we learn to articulate astoundingly skilled motions through our fingers without even being consciously aware that we’re doing anything at all.

I’ve constantly been staring at hands for over 20 years.

And yet I’m still constantly surprised.

People exhibit all sorts of manual behaviors, tics, and mannerisms, hiding in plain sight, that seemingly inhabit a strange shadow-world — the realm of the seen but unnoticed — because these behaviors are completely obvious yet somehow they still lurk just beneath conscious perception.

Nobody even notices them until some acute observer takes the trouble to point them out.

For example:

Take a behavior as simple as holding a pen in your hand.

You hold the pen to write, of course, but most people also tuck the pen between their fingers to momentarily stow it for later use. Other people do this in a different way, and instead palm the pen, in more of a power grip reminiscent of how you would grab a suitcase handle. Some people even interleave the two behaviors, based on what they are currently doing and whether or not they expect to use the pen again soon:

Illustration of tuck grip (left) vs. palm grip (right) methods of stowing the pen when it is temporarily not in use.

This seems very simple and obvious, at least in retrospect. But such behaviors have gone almost completely unnoticed in the literature, much less actively sensed by the tablets and pens that we use — or even leveraged to produce more natural user interfaces that can adapt to exactly how the user is currently handing and using their devices.

If we look deeper into these writing and tucking behaviors alone, a whole set of grips and postures of the hand emerge:

A simple design space of common pen grips and poses (postures of the hand) in pen and touch computing with tablets.

Looking even more deeply, once we have tablets that support a pen as well as full multi-touch, users naturally want to used their bare fingers on the screen in combination with the pen, so we see another range of manual behaviors that we call extension grips based on placing one (or more) fingers on the screen while holding the pen:

Much richness in “extension” grips, where touch is used while the pen is still being held, can also be observed. Here we see various single-finger extension grips for the tuck vs. the palm style of stowing the pen.

People also exhibited more ways of using multiple fingers on the touchscreen that I expected:

Likewise, people extend multiple fingers while holding the pen to pinch or otherwise interact with the touchscreen.

So, it began to dawn on us that there was all this untapped richness in terms of how people hold, manipulate, write on, and extend fingers when using pen and touch on tablets.

And that sensing this could enable some very interesting new possibilities for the user interfaces for stylus + tablet computing:

Watch Context Sensing Techniques for Tablet+Stylus Interaction video on YouTube

This is where our custom hardware came in.

On our pen, for example, we can sense subtle motions — using full 3D inertial sensors including accelerometer, gyroscope, and magnetometer — as well as sense how the user grips the pen — this time using a flexible capacitive substrate wrapped around the entire barrel of the pen.

These capabilities then give rise to sensor signals such as the following:

Sensor signals for the pen’s capacitive grip sensor with the writing grip (left) vs. the tuck grip (middle). Exemplar motion signals are shown on the right.

This makes various pen grips and motions stand out quite distinctly, states that we can identify using some simple gesture recognition techniques.

Armed with these capabilities, we explored presenting a number of context-appropriate tools.

As the very simplest example, we can detect when you’re holding the pen in a grip (and posture) that indicates that you’re about to write. Why does this matter? Well, if the touchscreen responds when you plant your meaty palm on it, it causes no end of mischief in a touch-driven user interface. You’ll hit things by accident. Fire off gestures by mistake. Leave little “ink turds” (as we affectionately call them) on the screen if the application responds to touch by leaving an ink trace. But once we can sense it’s your palm, we can go a long ways towards solving these problems with pen-and-touch interaction.

To pull the next little rabbit out of my hat, if you tap the screen with the pen in hand, the pen tools (what else?) pop up:

Tools specific to the pen appear when the user taps on the screen with the pen stowed in hand.

But we can take this even further, such as to distinguish bare-handed touches — to support the standard panning and zooming behaviors —  versus a pinch articulated with the pen-in-hand, which in this example brings up a magnifying glass particularly suited to detail work using the pen:

A pinch multi-touch gesture with the left hand pans and zooms. But a pinch articulated with the pen-in-hand brings up a magnifier tool for doing fine editing work.

Another really fun way to use the sensors — since we can sense the 3D orientation of the pen even when it is away from the screen — is to turn it into a digital airbrush:

Airbrushing with a pen. Note that the conic section of the resulting “spray” depends on the 3D orientation of the pen — just as it would with a real airbrush.

At any rate, it was a really fun project that garnered a best paper award,  and a fair bit of press coverage (Gizmodo, Engadget, & named FastCo Design’s #2 User Interface innovation of 2014 (paywalled), among other coverage). It’s pretty hard to top that.

Unless maybe we do a lot more with all kinds of cool sensors on the tablet as well.

Hmmm…

You might just want to stay tuned here. There’s all kinds of great stuff in the works, as always (grin).

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Hinckley, K., Pahud, M., Benko, H., Irani, P., Guimbretiere, F., Gavriliu, M., Chen, X., Matulic, F., Buxton, B., Wilson, A., Sensing Techniques for Tablet+Stylus Interaction.  In the 27th ACM Symposium on User Interface Software and Technology (UIST’14).   Honolulu, Hawaii, Oct 5-8, 2014, pp. 605-614. http://dx.doi.org/10.1145/2642918.2647379

• [PDF] [video – mp4] [Watch on YouTube]
• Best Paper Award (UIST 2014)
• Named FastCo Design’s #2 User Interface Innovation of 2014.
• I also have a talk available about this work, which I presented at the WIPPTE workshop.