sensations on your phone!
Then we need means of classifying and organizing collections. Haptic language and cultures of meaning are still in active development. Without a commonly shared lexicon, organization dimensions, or even adjectives, it is difficult to curate collections. Compare this to sound: most musical terms have a long tradition with a clearly defined lexicon (e.g., crescendo, staccato); non-musical sound effects generally “sound like” something, and are often literal. With vision, one does not have to be a graphic designer or artist to instinctively understand “warm” and “cool” colors; the color wheel is introduced to us in grade school.
Overviews allow us to skim collections. Visual or physical collections of examples are often displayed spatially for ambient reference or to enable quick scanning. When you cannot feel multiple things, it can be hard to get the big picture or swiftly peruse a collection. Both designer and end-users have needs for finding similar/different vibrations in a collection, requiring a low barrier-to-entry on any overview technique.
Given the importance of browsing, it is no surprise that the haptics community has made some progress. Libraries such as the Haptic Touch toolkit [Ledo et al. 2012, HapticTouch Toolkit 2016] or Penn Haptic Texture toolkit [Culbertson et al. 2014, Penn Haptic Texture Toolkit 2016] are available to the community. The Haptic Camera allowed for easy capturing of door knob dynamics that can be stored and recreated later [MacLean 1996], inspiring similar camera-like devices like a portable texture recording device [Burka et al. 2016]. VibViz [Seifi et al. 2015, VibViz 2016] is an online, visualized collection of vibrotactile icons that explicitly tackles these issues, providing multiple classifications schemes (facets) and visualizations to rapidly skim and find vibrations. Visualization techniques are still early, but they help [Seifi et al. 2015], and careful design can help improve representation of perceptual qualities [Schneider et al. 2016].
Sketch
Sketching allows people to form abstracted, partial views of a problem or design, iterate very rapidly and explore concepts. This is mostly heavily used early in design, and plays a role in collaboration (discussed more under “Share” below). Of course, such a central technique is used as a key way of thinking about experience design [Buxton 2007]; some even consider sketching to be the primary language of design, equivalent to mathematics as a language for natural sciences [Cross 2006]. With haptic technology, there is no immediate way to handle two essential features: abstraction and ambiguity, and rapid iteration (addressed more fully in Section 3.4.3).
With respect to abstractability, we note that haptics suffers from a dearth of notation. Sketching of physical devices or interfaces is well supported, with paper and pencil and innumerable software assists. Sketching motion, and in particular showing what is or might be felt in, say, a vibrotactile experience, is trickier. While we can sketch a visual interface and look at it, it is much harder to sketch a haptic sensation and imagine it without feeling it.
Creative approaches are emerging. Most directly, Moussette and Banks [2011] teach Haptic Sketching [DesignThroughMaking 2016] with physical scraps and materials, combined with manual actuator and tools like Arduino, to build effective interactive haptic prototypes physically and programmatically in minutes or hours. Simple display-only sensations can be sketched (e.g., VT icons) using interactive design tools [Schneider and MacLean 2014, Hong et al. 2013].
Refine
Clearly apparent in Figure 3.4, design requires iteration to refine an initial set of ideas into a single well-developed one through concept generation followed by iterative revision, problem-solving and evaluation, until only small tweaks are necessary. This long view of the design process is necessary to see designs through to the end; furthermore, tweaking final designs is a valuable way to accommodate individual differences.
Incorporating haptic technology into a design is an extremely vertical process, dependent on specifics of hardware, firmware, software, application, and multimodal context (Section 3.1.6). With the complexity of these many components, there can be a significant initial cost to setup a first haptic experience; then, adding this complexity to the time needed to program, recompile, or download to a microcontroller means iteration cycles have the potential to be slow and painful. Thus, increasing refinement fluidity is ripe for innovation. For example:
Pipelines now connect initial design seamlessly through to final refinement [Schneider et al. 2015b, Schneider and MacLean 2016]. Continuity in future tools will provide fluid, transparent (rather than cumbersome, many-staged) connection between hardware and software tools at different design stages.
Evaluation is as crucial as for any human-centered refinement cycle. While it will often require some form of sharing (coming up next), here we simply point out that the full spectrum of evaluative mechanisms and supports found in user experience development can be gainfully applied to haptic design, from lab-based comparative performance studies to qualitative examination of how usage strategies change when a physical dimension is deployed (e.g., [Minaker et al. 2016]).
Customization tools are appearing at least at the level of prototyping and requirements generation [Schneider et al. 2015a, Seifi et al. 2014]. Force-feedback virtual environments support iteration and refinement through code, once the initial environment is setup. Software platforms like Unity [Unity Game Engine 2016] offer immediate control of variables in the UI itself.
Tool context—calibration, customization, and sensing—in tools will help final haptic designs remain consistent depending on user activity (e.g., running impairs vibration sensitivity), individual differences, or other contextual concerns.
Share
Sharing designs is valuable at different stages of the design process [Kulkarni et al. 2012], whether for informal feedback from friends and colleagues, formal evaluation when refining designs, or distributing to the target audience for use and community for re-use [Shneiderman 2007].
As haptic experiences must be felt, this process works best when collocated with only a few collaborators, whether by having collaborators work in the same lab, or by showing final experience in physical demos. During ideation, ideas can be generated when collaborating remotely, but physical devices need to be shipped back and forth and it is difficult to troubleshoot and confirm that configuration and physical setup are the exact same. Feedback also typically needs to be collocated, using in-lab studies or feedback, or shipping devices between collaborators. Furthermore, visual and audio design support very easy capture of ideas to share later, through smartphone cameras and microphones, that could later be browsed.
So far, haptic broadcasting, analogous to broadcasting radio or television (e.g., Touch TV [Modhrain and Oakley 2001]) has been envisioned and explored. Follow-up work has added haptics to YouTube [Abdur Rahman et al. 2010] and movies [Kim et al. 2009]. Low-cost devices like the HapKit [Orta Martinez et al. 2016, Hapkit 2016] and Haply [Gallacher et al. 2016, Haply 2016] make haptics more ubiquitous, but remain troublesome to calibrate. To share ideas remotely on phones, proxies like visualizations or other types of haptics (phone vibrations) could be used [Schneider et al. 2016, HapTurk 2016]. Features like automatic calibration and proxies for use in online evaluation, and online communities more generally, are still in development.
3.4.2 Schemas for Design
Because haptic design is such a young field, there are many ways to approach it. One is to consider analogies to other fields, for example to draw on existing expertise in making sounds and multimedia. Another is to focus on the language of haptics, affect, and descriptive aspects of sensations, as laid out in
