Browsing by Author "Jota, Ricardo"

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    A comparison of ray pointing techniques for very large displays
    (Canadian Information Processing Society, 2010) Jota, Ricardo; Nacenta, Miguel A.; Jorge, Joaquim A.; Carpendale, Sheelagh; Greenberg, Saul
    Ray-pointing techniques are often advocated as a way for people to interact with very large displays from several meters away. We are interested in two factors that can affect ray pointing: the particular technique's control type, and parallax. Consequently, we tested four ray pointing variants on a wall display that covers a large part of the user's field of view. Tasks included horizontal and vertical targeting, and tracing. Our results show that (a) techniques based on 'rotational control' perform better for targeting tasks, and (b) techniques with low parallax are best for tracing tasks. We also show that a Fitts's law analysis based on angles (as opposed to linear distances) better approximates people's ray pointing performance.
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    The Continuous Interaction Space: Integrating Gestures Above a Surface with Direct Touch
    (2009-04-29T19:57:06Z) Marquardt, Nicolai; Jota, Ricardo; Greenberg, Saul; Jorge, Joaquim A.
    The advent of touch-sensitive and camera-based digital surfaces has spawned considerable development in two types of hand-based interaction techniques. In particular, people can interact: 1) directly on the surface via direct touch, or 2) above the surface via hand motions. While both types have value on their own, we believe much more potent interactions are achievable by unifying interaction techniques across this space. That is, the underlying system should treat this space as a continuum, where a person can naturally move from gestures over the surface to touches directly on it and back again. We illustrate by example, where we unify actions such as selecting, grabbing, moving, reaching, and lifting across this continuum of space.
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    The Continuous Interaction Space: Interaction Techniques Unifying Touch and Gesture On and Above a Digital Surface
    (2011-01-28T18:00:55Z) Jota, Ricardo; Marquardt, Nicolai; Greenberg, Saul; Jorge, Joaquim
    The rising popularity of digital table surfaces has spawned considerable interest in new interaction techniques. Most interactions fall into one of two modalities: 1) direct touch and multi-touch (by hand and by tangibles) directly on the surface, and 2) hand gestures above the surface. The limitation is that these two modalities ignore the rich interaction space between them. To move beyond this limitation, we first contribute a unification of these discrete interaction modalities called the continuous interaction space. The idea is that many interaction techniques can be developed that go beyond these two modalities, where they can leverage the space between them. That is, we believe that the underlying system should treat the space on and above the surface as a continuum, where a person can use touch, gestures, and tangibles anywhere in the space and naturally move between them. Our second contribution illustrates this, where we introduce a variety of interaction categories that exploit the space between these modalities. For example, with our Extended Continuous Gestures category, a person can start an interaction with a direct touch and drag, and then naturally lift off the surface and continue their drag with a hand gesture over the surface. For each interaction category, we implement an example (or use prior work) that illustrates how that technique can be applied. In summary, our primary contribution is to broaden the design space of interaction techniques for digital surfaces, where we populate the continuous interaction space both with concepts and examples that emerge from considering this space as a continuum.