624 #2 Specifying Gestures By Examples: Dean Rubine

Rubine specifies a technique for gesture recognition using 13 features of the gesture. Using these 13 features with a linear classifier it can generally recognize a gesture to 90% accuracy with 15 pre-defined examples of each class. These gestures must have a known start and stop point to be able to be classified, so only individual parts of a sketch can be used.

It will be interesting to implement Rubine's but what will be more interesting is to use some of the extensions discussed at the end of the paper. The most interesting will be implementing this with multitouch to create my own multifinger gesture recognition.

624 #1 Gesture Recognition: Tracy Hammond

This paper is an overview of a few techniques for basic pen gesture techniques. Note that these techniques are generally only good for recognizing a single stroke gesture and nothing more complex than that.

The first technique introduced is Rubines features. These features can distinguish gestures classes by using around 15 training examples. Rubines technique uses linear classifiers to compare a new gesture to all known classes and can distinguish between similar objects at different orientations. Long's feature set can be added to Rubines, but they do not add much additional capability at the cost of additional complexity and so they are not often used.

The second technique addressed is that of Wobbrock, the "$1 Gesture Recognizer". Wobbrock's method is simpler than Rubine's, however it is slower and unable to differentiate gestures that have been rotated or stretched.

624 #0 Self Introduction

Email: eyce9000 at gmail dot com

Standing: 1st Year MSCS

Taking this class: Because sketch recognition/machine learning are things I want to use in projects.

Experience: Not much directly useful to SR, but I am a sharp cookie (mmm cookies)

Doing in 10 years: Living somewhere by the sea, making awesome gizmos

Next Tech Advance: Memresistors!

Favorite Undergrad Course: Figure Drawing.

Favorite Movie: Kung Fu Panda, mostly because it has great character animation and because Jack Black is awesome.

Time Traveler: I would travel back to meet Steve Jobs and Wozniak right when they started Apple. Then I would go meet Bill Gates when he started Microsoft.

Interesting Fact: I lived in Italy when I was little, and got engaged this summer!

Fitts' Law

Fitts Law

It is nice to know that there are actual scientific and quantifiable ways to approach study of interaction. Fitts law shows us that we can actually model people's interaction with systems in a quantifiable way, by relating the number of errors in using an interface element to its proximity and size.

I suspect that microsoft has begun to use Fitts' law in designing some of their newer software, such as the "ribbon" interface of MS Office. I say this because they make use of buttons in the interface whose size is dependent on how important they are. Also the buttons are arranged so that they are closer together, making errors less likely once the system is known.

The Inmates are Running the Asylum

The Inmates are Running the Asylum

Alan Cooper

This book is essentially an argument for the existence of interaction design consultants. It discusses the problems associated with giving the task of interface design to managers, marketers and programmers and argues for the use of interaction designers to completely design the system before any implementation is begun.

I agreed with much of what this book had to say about not only managing projects but also about the design process and attitudes of software engineers. I have seen much of what the author mentions in my own projects, where I get so caught up in what I have to do to program a project that I lose track of how people will ultimately use it. I think in terms of which features I want to have and not necessarily in what is needed to support a specific activity or fulfill a need. When engineering software I feel extremely liberated when I do not have to come up with the interaction design as well and can just focus on getting an already agreed upon design constructed correctly. However I do not feel their should be a complete disconnect between those who implement software and those who design the interactions, and neither does the author. Designers need to understand what is required to implement their designs, and most importantly need to understand what sort of interactions are feasible. That is not to say they should be conservative with their designs just because of their knowledge of the implementation, but they should be able to balance optimal interaction with reasonable implementation.

If and when I go into the software industry, I plan to make sure every software engineer I meet has read this, if only to make sure they acknowledge some of the problems associated with the software engineering mindset.

Providing Dynamically Changeable Physical Buttons on a Visual Display

Providing Dynamically Changeable Physical Buttons on a Visual Display

Chris Harrison Scott E. Hudson

This paper discusses work by the authors to create a simple and versatile system for dynamic buttons on visual displays. Their system involves the use of a malleable latex membrane that can be backlit to act as a screen, a vacuum to distort the latex and a backing that is used to create specific shapes with the distorted latex. The purpose of this interface is to add an element of physical feedback and interaction to touch screens.

While adding their system to generally static touchscreens can be useful in many specific applications (such as car interfaces, ATM pin pads etc.) the lack of dynamism limits its use in my opinion. They make the point that the backing is easy to produce and change, making it simple to create new physical interfaces for systems. However, this is not truly dynamic and almost defeats the purpose of using touch screens for interaction (that interaction can be defined programmatically to support a variety of activities). If you are presented with a "dynamic" pin pad interface, there is only so many different activities you can map onto a pad with 3 rows of 3 buttons, even if those buttons could be enabled or disabled separately.

In spite of these reservations, I feel this could be a significant boon to some of the applications suggested in this paper, specifically car dashboards and control panels. These interfaces do not need to be too dynamic and are significantly easier and safer to use when they can be operated by touch instead of sight. This system combines the advantages of physical interfaces with some of the dynamic ability of touch display systems.

Human Centered Design Considered Harmful

Human Centered Design Considered Harmful

Donald "Don" A. Norman

In this article, Don Norman discusses some of the problems of focusing on the "user" for design. In particular he feels that designing specifically for the user should perhaps be replaced with designing for an activity or task. In designing for the user we often overlook what it is the user is actually trying to achieve and what sort of inherent design issues are present in the activity, and instead focus on trying to make the interface human friendly. As he points out in the article, well used systems such as musical instruments and handwriting are well adapted to their specific activities but are on the whole not very "Human friendly".

I like the points Norman makes in this article. Personally I feel the best interface is the one that supports the quickest and most efficient way to perform an activity or task. Once the interface is constructed with this in mind we can then go back and use Human centered design techniques to refine the interface with human use in mind.