Article Review - User Studies for Touch-Screen Interfaces

Howdy!

Today, I looked a research paper from 2009 entitled Evaluation of User Interface Design and Input Methods for Applications on Mobile Touch Screen Devices. In a deviation from the augmented reality studies, this paper performed a user study to try and determine the "best" interface design for mobile touch-screen devices. They commented that previous studies had given somewhat vague guidelines on what a good interface "should" be, but they wanted to compare very specific UI techniques and gain empirical data.

(image from the paper)

To do this, they looked at three different aspects of mobile application interfaces. First, they compared a scrollable layout to a tabbed layout by having users navigate to different pages. An interesting finding here was that even though the scrollable layout had faster results, a qualitative questionnaire revealed that users seemed to prefer the aesthetics of the tabbed layout. Next, they had users edit their profiles with modal dialogs (i.e. date picker) versus non-modal input methods (directly entering with the keyboard). For this task, the clear winner in both timing and preference was the non-modal form of entry, probably because users were more accustomed to the standard QWERTY keyboard; this might yield different results with today's users. Finally, they had users navigate a list and use a menu to perform various operations on each element, once with a context menu (long press) and once with the physical menu button. In this case, the physical button won out in both timing and usability simply because the users felt the context press was not very intuitive. Even by today's menu standards, I tend to agree with these results.

The biggest drawback of this usability study was the small experimental group, although it did help that the researches had a variety of ages and experience levels within that small group. Usability is something often overlooked, and so the more research efforts like these, the better.

Thanks and gig 'em!

Balagtas-Fernandez, Florence; Forrai, Jenny; Hussmann, Heinrich; "Evaluation of User Interface Design and Input Methods for Applications on Mobile Touch Screen Devices," Human-Computer Interaction – INTERACT 2009. Lecture Notes in Computer Science, pp.243-246.
doi: 10.1007/978-3-642-03655-2_30
Url: http://dx.doi.org/10.1007/978-3-642-03655-2_30

Article Review - "Massively Multi-user AR"

Howdy!

Today, I looked at a research paper from 2005 entitled Towards Massively Multi-user Augmented Reality on Handheld Devices. The Austrian team behind it was one of the first groups to try and get away from the cumbersome augmented reality setups that the field began with, including the backpacks, wearable desktop computers, goggles, etc. They identified three devices that are generally more accessible and socially fitting: PDAs, phones, and tablets. At the time of their research, 3D acceleration and high processing power was not as readily available as today, and powerful phones and tablets were scarce and extremely expensive, so they chose the PDA with an attachable camera add-on as the platform to conduct their research.

(system architecture, image from the paper)

The architecture they chose is displayed above. The only two components they had to build from scratch were PocketKnife, a hardware abstraction layer designed to be platform-independent and ease the development of graphical applications on mobile devices, and KLIMT, a renderer similar to OpenGL (which was not available for mobile devices at the time of the research). Every other system component was open-source, including the tracking software (OpenTracker), scene-graph renderer (Studierstube), and distributed networking framework (ACE); the team just put the pieces together in the right way.

(Invisible Train game, image from paper)

To actually test and evaluate this system, they built a game-like application (pictured above) that was designed for easy use by the general public, including children. Essentially, it was a multi-player train simulator where participants could choose to play collaboratively (trying to avoid hitting each others' trains) or competitively (trying to crash into each other). They launched the game in four locations simultaneously and supported several thousands of users over multiple days, which was an order of magnitude larger test group than had been previously used in AR research (according to the team). They gathered very informal evaluative information from the participants in the form of questionnaires and interviews, and on the whole there was a positive response. They felt they achieved a landmark goal in the quest of "AR anytime, anywhere".

Speaking from a present-day view, this research effort does seem to be a big step in the right direction, as there have been AR applications built since then on the concept of a massive user-base. It is also a positive takeaway for our own project that they managed to build this application using so many existing open-source components.

Wagner, Daniel; Pintaric, Thomas; Ledermann, Florian; Schmalstieg, Dieter; "Towards Massively Multi-user Augmented Reality on Handheld Devices," Pervasive Computing, 2005. Lecture Notes in Computer Science, pp.77-95.

doi: 10.1007/11428572_13
URL: http://dx.doi.org/10.1007/11428572_13

Article review - "Cultural Heritage Layers"

Howdy!

Today, I'll be looking at an article from 2009 that discusses an augmented reality application coined "Cultural Heritage Layers". The research team involved in this system had a problem with existing cultural heritage AR projects due to their lack of marker-less tracking systems and doubtful scientific accuracy, as well as the fact that they tend to be built on proprietary (and therefore unsustainable) software. For tackling the first issue, the team built a simple but effective two-step process that the system goes through to learn locations from reference images.

(figure taken from article)

First, randomized trees are constructed based off detectable "key points" of a video frame; these patches are then tracked based on their alignment to the reference image (the tracking is just done via a local search algorithm). This method seems pretty cool to me, although I wish the authors had gone into more detail concerning the feature-detection. They did claim that this method made testing and verification extremely easy, since you could basically just use cardboard cutouts to simulate large buildings.

As far as actually setting up the scene, they relied on a fairly lightweight framework called X3D that just needed minimal OpenGL and 3D acceleration - mostly because they only used 2D textures of historic buildings and scenes, as opposed to actual 3D models. An X3D scene is basically made up of the camera image in the background, a fixed filling quad to display the footage, and a flat ImageTexture node. The idea is that those who wish to set up their own scenes with various options for interactivity can just throw them on top of this node with an extremely small amount of code (the authors claim that only one line of X3D code is needed per point of interest). To demonstrate the system, they briefly described two in-use applications. The first, a visual look at the history of the Berlin Wall, allows users to cycle through historical images by touching the virtual scene on their mobile display. the other, an Italian heritage site called Reggia Vernaria Reale, actually renders the "real" scene differently depending on the image being displayed. For example, a particularly old black and white photo of Italian architecture will draw all people, environments, and real buildings as black and white so that the scene looks seamlessly enhanced with the virtual building.

(figure taken from article)

The work being done here could apply to our system in a few different ways, including the idea of interactivity, 2D image overlays, and tracking. What I really like about this Cultural Heritage Layers project is that it didn't introduce some dazzling new AR algorithm that involved laborious computer vision techniques, but instead focused on existing technologies, an interesting and profitable domain, and usability. Those are the features that AR work needs to improve upon if it is ever to be adopted on a mass scale.

Thanks and gig 'em!

Zoellner, M.; Keil, J.; Drevensek, T.; Wuest, H.; , "Cultural Heritage Layers: Integrating Historic Media in Augmented Reality," Virtual Systems and Multimedia, 2009. VSMM '09. 15th International Conference on , vol., no., pp.193-196, 9-12 Sept. 2009
doi: 10.1109/VSMM.2009.35
URL: http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=5306012&isnumber=5305995

Augmented Reality article review

Howdy!

Today, I'll look at a SIGGRAPH article from 2005 that discusses augmented reality (AR) interfaces by breaking them down into abstract components. The authors begin by stating that AR has not yet made significant progress beyond the first stage of new interface development - the prototype demonstrations. They claim that while there exist very interesting and intuitive systems for viewing three-dimensional information using AR, there is still very little support for actually creating or modifying content. This claim could probably be argued against in recent years with applications like AR graffiti being developed, but as a field, I still think there is a ton of work to be done in AR

content modification and creation. The article does do a great job of breaking down AR into three

distinct componentS: the physical elements, the display elements, and the interaction metaphor that

links them. The first two parts are probably the easiest to encapsulate and define, and as such,the

interaction metaphors are still fairly limited.

The authors attempt to deal with this limitation by sharing what they call "tangible user interfaces,"

and they go into details of a couple case studies of their own work. The first one, AR MagicLens,

allows users to view inside virtual datasets. The physical elements for this sytem are a simple paper

map for the virtual coordinates and a small ring-mouse that the user can hold. The defined

interaction metaphor is the ability of the user to hold a virtual magnifying glass and peer inside

virtual sets of data. An example they gave was a virtual model of a house that, when viewed with the

virtual magnifier, exposed its frame (also virtually). The second case study, mixed reality

art, basically allowed the user to combine real painting tools with virtual paint, bridge surfaces,

and polygonal models to create virtual works of art on real surfaces.

Both of these case studies are pretty cool, and it would make sense that they probably served as a

basis for other AR applications in the past few years. For our capstone project, I could see the

research of the "mixed reality art" being quite helpful.

That's it for today. Thanks and gig 'em!

article info:
Billinghurst, Mark; Grasset, Raphael; Looser,

Julian; "Designed augmented reality interfaces,"

ACM SIGGRAPH Computer Graphics - Learning through

computer-generated visualization, Volume 39 Issue

1, February 2005.

http://dl.acm.org/citation.cfm?id=1057803