From Touchpad to Smart Lens: A Comparative Study on Smartphone Interaction with Public Displays

Today’s smartphones provide the technical means to serve as interfaces for public displays in various ways. Even though recent research has identified several new approaches for mobile-display interaction, intertechnique comparisons of respective methods are scarce. The authors conducted an experimental user study on four currently relevant mobile-display interaction techniques (‘Touchpad’, ‘Pointer’, ‘Mini Video’, and ‘Smart Lens’) and learned that their suitability strongly depends on the task and use case at hand. The study results indicate that mobile-display interactions based on a traditional touchpad metaphor are time-consuming but highly accurate in standard target acquisition tasks. The direct interaction techniques Mini Video and Smart Lens had comparably good completion times, and especially Mini Video appeared to be best suited for complex visual manipulation tasks like drawing. Smartphone-based pointing turned out to be generally inferior to the other alternatives. Examples for the application of these differentiated results to real-world use cases are provided. DOI: 10.4018/jmhci.2013040101 2 International Journal of Mobile Human Computer Interaction, 5(2), 1-20, April-June 2013 Copyright © 2013, IGI Global. Copying or distributing in print or electronic forms without written permission of IGI Global is prohibited. such as built-in sensors, high quality cameras, and increasing processing power, they enable several advanced techniques to interact with large public displays. Ballagas et al. (2006) investigated the available input design space and came up with different dimensions for classifying existing mobile/display interaction techniques. E.g. they suggest distinguishing between relative and absolute input commands as well as between continuous and discrete techniques. A continuous technique may change an object position continually, using a discrete technique the object position changes at the end of the task. Another commonly used dimension is the type of directness of a technique. A direct technique allows for the immediate selection of a favored point on the screen through the mobile device, traditionally using a graphical approach. In contrast, indirect approaches make use of a mediator, typically an on-screen mouse cursor which can be controlled through the mobile device. Following an early classification of interaction techniques (Foley et al., 1984) we extend this smartphone/display interaction design space by the dimension of orientationawareness taking into account the increasing popularity of mobile gesture-based applications. In case of an orientation-aware technique the position and/or orientation of the mobile device affects the interaction with the screen. In contrast, orientation-agnostic approaches are not sensitive to device movement. To learn more about upcoming orientationaware interaction techniques and to evaluate their suitability for spontaneous interaction with public displays in comparison to established techniques, we selected four recent techniques for an in-depth comparative study. We decided to choose two novel orientation-aware interaction techniques which are gaining increasing attention in industry and academia. These techniques became feasible on smartphones only recently due to advances in mobile device technology. Respective implementations have not been scientifically compared with existing more established techniques so far. Thus their actual benefits in terms of performance and user acceptance have not been proven by now. The first orientation-aware aware technique, the Pointer (Figure 2), is made possible due to gyroscopes integrated into mobile devices of the latest generation. Inspired by a laser pointer, this technique enables the control of the mouse cursor by tilting and thus literally pointing towards the favored display location with the mobile device. The second orientationaware, yet direct Smart Lens technique (Figure 4) enables screen interaction over the live video of the smartphone. By targeting respective areas of the remote screen through the built-in camera users may select a specific screen point by touching the mobile device display. Since this direct technique works directly on the device’s live video, it inherently offers a zoom feature by reaching out and moving the device closer to the display and vice versa. As more established techniques for our comparison we chose two orientation-agnostic interaction approaches with implementations already publicly available in mobile application stores. These two techniques represent respective counterparts to the abovementioned novel ones according to the dimension of directness. The indirect Touchpad technique (Figure 1) makes use of a common interaction style and exploits the touchscreen of the mobile device in analogy to the touchpad of a notebook computer: strokes on the touchscreen are reflected by respective mouse cursor movements on the remote screen. Finally, Mini Video (Figure 3) represents an orientation-agnostic direct interaction technique showing a cloned miniature view of the large display on the mobile device. Touches on the smartphone display are directly mapped to corresponding large display coordinates. 18 more pages are available in the full version of this document, which may be purchased using the "Add to Cart" button on the product's webpage: www.igi-global.com/article/touchpad-smartlens/77620?camid=4v1 This title is available in InfoSci-Journals, InfoSci-Journal Disciplines Communications and Social Science, InfoSciSelect, InfoSci-Select, InfoSci-Technology Adoption, Ethics, and Human Computer Interaction eJournal Collection, InfoSci-Networking, Mobile Applications, and Web Technologies eJournal Collection, InfoSci-Journal Disciplines Computer Science, Security, and Information Technology, InfoSci-Journal Disciplines Engineering, Natural, and Physical Science. Recommend this product to your librarian: www.igi-global.com/e-resources/libraryrecommendation/?id=2