Insights into designing successful user experiences for digital tabletops.
In my previous post, I discussed good reasons to deploy digital touch tables in exhibitions. In this post, I’ll sketch out some approaches to designing user experiences for the form factor.
To begin, let’s take a look at an often unsuccessful use of this technology: Presenting existing video, presentations, websites, and digital interactives on a digital tabletop without modification is usually a bad idea, for a number of reasons primarily related to ergonomics.
Tabletop Ergonomics
Depending on the scale of the table, reading or viewing content that spans its display can be akin to sitting in the first row at a movie theater. The closest edge of the table is comfortably parallel to the plane of our eyesight; as we look across the table, the farther our view gets from this edge, the more skewed the content. Think of a laptop or tablet – our natural instinct is to hold it parallel to our face so our gaze sits in the center of the screen. That’s not possible on most tabletops, nor can we easily move closer to or further from the screen.
Similarly, the tabletop form factor impacts touch interaction. A typical application might place its core navigation at the top of the screen; depending on the digital tabletop’s size, reaching across may be awkward or even impossible, particularly for very young visitors. The flip side of this is accidental touch interaction; interaction points at the bottom of the screen may be accidentally triggered as visitors lean across to reach the center of the table.
One way around this, which can be seen in many custom tabletop applications, is to create smaller interaction zones along the edges of the table, which allow each user to peruse content from a comfortable vantage point. We’ll refer to this as the “Station” model.
Multi-Station Approaches
The Station model is one of the most commonly seen interface structures for digital tabletops, as it resolves many of the ergonomic challenges of the form factor while empowering parallel individual experiences. Some factors to consider when taking this approach include:
- Screen real estate: When splitting the screen, how much space does each user need to interact and consume media? The more divided the surface, the lower the resolution of each station, which may become an issue for text heavy applications (though Ideum’s 4K touchtables provide a high-detail solution).
- Physical real estate: How much physical distance do users need from one another to avoid feeling claustrophobic? The answer may vary depending on audience, as schoolchildren will have different personal boundaries than business customers, for example.
- The social element: At its worst, the station model is simply recreating single-user kiosks side-by-side on a large screen. Are there ways to create user stations that aren’t siloed from each other? Are there ways to encourage interaction between the stations, or create elements at the table’s center that can be shared by all the users?
- Fixed vs. Dynamic: In some applications, visitors may create their own interaction stations, which can be moved freely around the table. This offers tremendous flexibility, but potentially introduces issues of crowding and occlusion.
- Playing nicely together: As with any multi-user application, experiences must address the question of how each user’s interactions affect others. Who initiates a shared experience, and who decides when it’s time to move on? In a game or creative activity, what happens when one user tries to interfere with another user’s progress? Prototyping with actual visitors is often the best way to resolve these questions, since user behavior with touch tables can be difficult to predict.
Angle of Approach
As most tabletop interactions are designed to accommodate multiple users, they will inevitably attract users to every edge of the table, meaning that text and media may appear upside-down or rotated to certain users. Here are a few potential approaches to accommodating this:
- Stations – As described above, the Station model’s fixed points of interaction, placed around the table’s edges, are each oriented to accommodate a user standing in front of them.
- Freeform – Freeform placement of content, “scattered” across the tabletop, lets visitors use intuitive gestures to move, scale, and rotate content as they see fit.
- Repeated – Text content is presented twice, at two angles of orientation, to accommodate each lengthwise table edge (the most common location for users to approach).
- Fixed – Nothing rotates, leaving it up to visitors to find and position themselves along the preferred reading axis. While this counters many of the benefits of the tabletop form factor, certain content (such as maps) may dictate this tactic. In these cases, it may be beneficial to position the display at a slight angle, like a drafting table, to delineate the preferred user position.
Object Recognition and Tracking
Physical object tracking is one of the most powerful features of digital tabletops. By reading visual tags, or patterns of capacitive material, tables can identify the location and orientation of objects placed on their surfaces, creating unique tactile experiences that blend the physical and digital.
The most common use for this technology is as a navigation content trigger – placing the object on the table ‘pops-up’ related content. This often works best when content sits within a small dynamic window that travels and rotates with the object; this allows users to resolve issues of overlap and spacing in a natural manner. When objects trigger full-screen content, it may be advisable to designate an interaction zone on the table where objects can be placed without occluding text and imagery.
Beyond content triggers, some good use cases for object tracking include gameboard avatar pieces, voting ‘chips’ for surveys or quizzes (using a roulette-style interface), and tactile controls for music and creative applications (like Microsoft’s Surface Dial).
There are great, structured ways to use objects on the table, but it’s important to accommodate for object mis-use (intentional or accidental). If an object triggers a full-screen of content, what happens when two objects are placed on the table simultaneously? And most importantly, what happens when triggers are lost, stolen or damaged? In my experience, object tracking is often value-engineered out of tabletop projects for this last reason. If that’s a concern, be sure to prepare duplicate backup objects or design them to be easily reproducible.
Best Practices, Anyone?
I’d planned to conclude this post by linking to some more robust articles about best practices for designing touch table experiences… only to discover that I couldn’t find any. Years ago, Microsoft had design guidelines for its Surface/PixelSense tables, but these are no longer available now that the products have been discontinued. I didn’t see anything comparable on the Ideum or MultiTaction websites, though both these vendors offer software packages that provide templated multi-touch solutions.
So, if anyone out there has info to share, please send it my way and I’ll update this post. In the meantime, I hope the thoughts above will prove helpful in envisioning and designing your own touchtable experiences.