Robert Pastel
Computer Science Assistant Professor

rpastel at mtu dot edu
204 Rekhi CS Hall
     
 
Research
 
Primarily, my research is in the broad area of Human-Computer Interaction (HCI). I deliberately choose to study HCI because it combines artistic sensibility with mathematical precision. An interface designer employs programming languages to create an interface to the computer which is both efficient and pleasant for users. Also HCI is more than static art work; user interfaces have utilitarian value and dynamically interact with both the user and the computer. Consequently, the interface designer should understand the user’s goals and cognitive processes. Finally, HCI is an interdisciplinary field. I collaborate with colleagues in Psychology, Humanities, Computer Engineering, Geospatial Information Systems and others.

Human - Computer Interface
  HCI research can be divided into three broad areas: interface design and implementation, interface software and hardware tool development, and interface theory and evaluation. These three areas (design, tools and theory) form the three supports that all user interfaces must be based on to be successful. My research spans all three areas.
Interface Design and Implementation
During HCI's infancy, designers primarily developed user interfaces for the desktop environment. User interactions with computers were restricted to these large machines. Today, users interact with palm size computers, smart phones such as the iPhone and the Android. Students in my undergraduate HCI course design and implement user interfaces for the Android.
 
Because users carry phones wherever they go and smart phones are equipped with Global Positioning Systems (GPS), smart phone applications can be aware of the user's location. The GPS in most smart phones have only 30 meter accuracy, but Wide Area Augmentation System (WAAS) corrections to GPS achieve one-meter accuracy. Tom Donahue, Konstantin Zhuravlyov, Dr. Eugene Levin and I have equipped an Android phone with WAAS GPS and propose new location-aware applications to Google.
 
I also advise the iPhone club, iPhone Developer Group. Corbin Uselton, Jun Ma and other students in the club are developing an iPhone interface to heart monitors. Haihua Li and I advised Ryan McMahon and Joshua Fahey developing a mobile website for the MTU library, Mobile Catalog.
 
  Because of their portability, personal digital assistants are attractive platforms for users that benefit from mobility, for example conducting laboratory or field experiments. Nathan Skalsky and I proposed a PDA-based science laboratory, PBL, and designed Experimental Assistant, an application for the TRIcorder.
 
Although I do not have much time to play computer games, I would enjoy moding or developing computer games. I believe that computer games push the frontier of computer technology and demonstrate new possibilities for more utilitarian HCI. Interface designers must consider that many future computer users are introduced to the computer via games and therefore are acquainted with alternative interfaces. I am the advisor for Husky Game Development (HGD) enterprise. Members of HGD enterprise design and implement games for the X-box, iPhone and Flash games for the web.
 
Interface Software and Hardware Tools
Computer mice and touch pads are unique peripheral devices and perform an essential function in HCI. They provide rapid and intuitive user input to the computer. The mouse was invented in 1964 by Engelbart, and by 1981 became popular in WIMP (windows, icons, menus and pointer) interfaces that have become ubiquitous in user interfaces. Pointing devices have developed little from point and click input for making a selection. I develop alternative interaction techniques and device drivers such as gesturing interfaces and gravity mouse.
 
Handhelds and smart phones are challenging platforms for interface design because of the restrictions imposed by the limited screen size and lack of keyboard. Dr. Chunming Gao, one of my PhD students, developed a single key text input technique using the accelerometer in smart phones for text input.
 
 

Gesturing interfaces can overcome many of the PDA challenges. In the paper “ Demonstrating Information in Simple Gestures ,” Nathan Skalsky and I introduced the Simple Gesturing User Interface, SGUI, for writing gestural interfaces on the palm pilot. SGUI is a fast and light weight gesture interpreter. Joseph Ross and Andy Spina have ported SGUI to Java, JavaSGUI.

 

Although the mouse appears to be under direct control of the user, mouse motions are interpreted by the driver and the operating system before the cursor is moved on the screen. Seldom is the cursor motion linear with the mouse motion. Frequently the cursor is accelerated for (e.g. moved trice as far) for fast mouse motions and not accelerated for slow mouse motions. This mouse-cursor transformation allows the user to move the cursor quickly for gross motions while still retaining accurate cursor control for fine motion. This separation of cursor from the mouse allows for the intelligent interfaces to assist the user. The interface knows the location of buttons; it can accelerate the cursor towards the button. Chris Fuller wrote GravityMouse, a Java class, and Paul Himes developed the test platform for GravityMouse. Our work is presented in the paper, "Gravity Mouse Design and Evaluation: Effects of Distracters and Target Size."
 

An alternative to using mice to make selections on the computer is to physically select objects and place them near a computer. Computer users could place objects tagged with Radio-frequency identification (RFID) tags near RFID scanners. The application program would then interpret the placement as a selection. Dr. Charles Wallace (Michigan Technological University), Dr. Jesse Heines (University of Massachusetts Lowell) and I designed an interface using "RFID Cards: A New Deal for Elderly Accessibility."
 
Interface Theory and Evaluation

There are few quantitative measures in HCI to determine interface effectiveness and efficiency. One quantitative measure is to time tasks performed on the computer. A simple task is moving the cursor to a button. Many computer scientists have confirmed that the time to move the cursor to a button is governed by Fitts's law. Fitts's law states that the movement time is logarithmically proportional to the initial cursor-target separation divided by the target width. Joe Vaillancourt (an undergraduate research student) developed a test platform for verifying Fitts's law.

I redesigned and implemented Joe Vaillancourt's test platform to evaluate positioning tasks. Positioning is precisely locating graphical objects. It is a generalization of the selection task used to verify Fitts's law. My work led to a three phase model for positioning.

 
  Designing Experimental Assistant, a graphing application using SGUI for gesturing, required a new design approach. Particular attention needed to be focused on the action of the interface objects. I called this design model "object-action association."
 

Johnny Accot and Shumin Zhai at IBM developed the steering law, which extends Fitts’s law to guiding the cursor through a prescribed path on the screen. The steering law and the accompanying theory provides a means to measure the efficiency of gesturing interfaces. Robert Moore, Jake Camplin, Scott Gross, and Dmitry Podkuiko have developed a test platform for verifying the steering law. My analysis is presented in "Measuring the Difficulty of Steering through Corners."

 
 

Nathan Paul, Matt Harper, Jake Champlin, and Arlo Moran extended the idea of steering to remotely navigating robots and developed the test platform using the UnReal game engine. The paper "The Difficulty of Remotely Negotiating Corners" attempts to determine a model.

In order to understand and quantify our results, I studied positioning in "The Difficulty of Centering Circular Discs."

 
Computer Science Education
Because a large part of my job is teaching (data structures and HCI), I have the opportunity to conduct research in computer science education. Surprisingly, computer science education research has generated new ideas for HCI research.
 
Human-Computer Interface Education

HCI is a neglected area in computer science pedagogy. Academics are debating what and how HCI should be taught. I proposed integrating science and research in an HCI design course.

Chris Brown, PhD student, and I developed a new course "Combining Distinct Graduate and Undergraduate HCI Courses: An Experiential and Interactive Approach." Undergraduate students design and implement user interfaces for the Android and graduate students evaluate and test their designs and applications.

Dr. Charles Wallace (Computer Science), Dr. Paul Ward (Psychology), Dr. Karla Kitalong (Humanities) and I propose extending this multidisciplinary teaching technique to a new program, Human Centered Computing (HCC). Students from Computer Science, Humanities and Psychology in cohort groups develop new products and applications for the community.

 
Data Structures Education

Attendees at a publisher’s symposium were interested in the development of group labs for the introductory data structures course. Because I developed physics group labs, I was interesed in developing group labs for the data structures course. I wrote several data structures group labs, and the paper "Student Assessment of Group Laboratories in a Data Structures Course" describes students' responses.

Chris Brown, PhD student, has developed a tool for automatically grading programming assignments using JUnit test. We are planning on presenting the tool at ACM Special Interest Group on Computer Science Education (SIGCSE).

 
Research Opportunities

If you are interested in research and like to program or designing interfaces, or working with people, there are many opportunities for you in HCI. Six graduate students and more than 30 undergraduates have work with me over the past several years.

If you are interested in any these research areas, or have research ideas of your own in HCI or computer science education, please see me. Undergraduate students can earn independent study credits and and graduate students can earn research credits.

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