Blog - Paper Reading #18

Biofeedback Game Design

Authored by Lennart E. Nacke, Michael Kalyn, Calvin Lough, and Regan L. Mandryk.

Clavin and Michael hail from the University of Saskatchewan where they are students working with Professor Mandryk. Lennart Nacke woks in games science as an assistant professor at UIOT. This paper was presented at the CHI '11 Proceedings of the 2011 annual conference on Human factors in computing systems.

Summary

Hypothesis 

The authors believed that a system of physiological sensors could be used to enhance games via biofeedback.

Methods

To test this hypothesis the authors conducted a series of tests using a game augmented with biofeedback. They aimed to answer two primary questions. The first was whether or not users would respond positively to games with controls augmented, rather than replaced, by these sensors. The second was to identify which sensors and mechanics were most effective.

Results

In general, feedback was positive. Users felt the sensors made the game more immersive though in some ways more complicated. Typically they expressed preference for the game mechanics that corresponded most directly to their representative physical inputs. 

Content

 The paper pretty effectively lays out the motivations for the project before beginning on the details of the test setup. The authors describe in detail the function of the various physiological sensors as well as their function in-game. After describing a short user study the paper discusses the feedback received which, overall, was positive.

Discussion

I thought the paper and the project itself were both well designed. I like that they are taking a less intrusive approach to modifying gaming design by simply modifying controls rather than attempting to completely replace them. This paper has particular interest to me in the context of the game scaling they provided based on physiological data. Being able to ramp up a games difficulty or even modify the content based on how stimulated a person is smacks of the makings of a "perfect game". This is a concept far removed from the present, but a game that is just right for each individual that plays it is a very intriguing thought. 

Blog - Paper Reading #15

Madgets: Actuating Widgets on Interactive Tabletops

Authored by Malte Weiss, FLorian SChwarz, Simon Jakubowski, Jan Borchers

Summary

Hypothesis
The authors hypothesize that tangible madgets will provide a useful way of interacting with widgets on an led surface. They also felt they could achieve a design that was simple to prototype and required no internal power supply.

Methods
For the display a TFT panel backlit by electroluminescent foil was used. The acryclic surface reflects diffused IR light into fiber optic cables to detect touch. Electromagnets positioned underneath the surface are wrapped in custom made shields to control their interaction with madgets.

Results
Using their design specifications the authors were able to create a flexible, lightweight widget that took less than an hour to manufacture. Their implementation for magnetic actuation was fully functional. They also designed a toolkit to ease integration of new actuated widgets into use with interactive surfaces.

Content
The focus of this paper is the design of madgets. It discusses anecdotal work that influenced the project, before detailing the construction of their surface. The paper then addresses the design constraints for the madgets themselves before discussing their construction. It then examines the uses of madgets through several models designed in the lab.

Discussion
I believe the authors achived their aims. Madgets are exceedingly easy to construct and are simply activated on the interactive surface. The paper lacked user studies, but this was more of a concept project. I do find it interesting that the authors hoped to design a product that could be manufactured on the fly for immediate use with an interactive tabletop. The thought of being able to design my own physical tools for use with a computer is quite intriguing. I would have liked to have seen more testing being done on the practical use of madgets, but I suppose that falls to future work.

Blog - Paper Reading #14

TeslaTouch: Electrovibration for Touch Surfaces

Authored by Oliver Bau, Ivan Poupyrev, Ali Israr, Chris Harrison.


The authors are all researchers at Disney Research in Pittsburgh with the exception of Chris Harrison who is a PhD student at Carnegie Mellon.


Summary

Hypothesis
The authors hypothesized that electrovibration could be an effective technique to provide tactile feedback for touch surfaces.

Methods
 Electrovibration was generated by sandwiching a transparent electrode between a glass plate and a resistive sheet. Several tests were conducted measuring baselines for this technology. 10 users participated and recorded results including absolute detection thresholds, amplitude and frequency discrimination thresholds, as well as simply characterizing the "feel" of different settings.

Result
Low frequency stimulus resulted in the surface feeling rougher as opposed to higher frequencies that felt smooth. High amplitudes caused the surface to feel more waxy as opposed to rubbery or sticky. One observed characteristic was that users did not interpret the sensation strictly as changing friction, they were able to detect both an element of friction and vibration simultaneously.

Content
The paper describes the prior work the project is based on, including the discovery of electrovibration. It then describes the physical setup of the surfaces utilizing TeslaTouch. The authors then conducted a user study to examine the baselines of electrovibration, as well as the general user response to the tool. The results led to an examination of the advantages this technique has over mechanical actuation. The authors conclude by examining potential uses for the product.

Discussion
I found the paper quite interesting. I think that the authors achieved their aim in proving electrovibration as an effective means of tactile feedback. The bit at the end of the paper about the parallel technology  being developed outside their labs seemed sketchy. Otherwise the project seems a solid academic development with real world applications.
It is interesting that this design has no actual moving parts. The authors give a very good argument for this quality. Moving parts all break down eventually. I see no limit to the uses for this product. Tactile feedback would be in some way useful for most all tasks on an interactive surface. As for future work, I would like to see the team work around the issue of only allowing one finger in motion at one time.