Tufts University

Factoring in the Human Element

Engineers get practical experience from professors

Students in Dan Hannon's class are getting first-hand experience in answering a common design question: How do you make a product better for people using it? By studying how real users work with a program like stop-action movies, or SAM, Hannon's students are gaining insight into what works and what doesn't work about design in a real-world setting—a field of study called engineering psychology, or human factors.

"Often, one of the biggest problems in design is that you design for yourself," says Hannon, an engineering psychologist who is also a full-time Professor of the Practice in the School of Engineering's mechanical engineering department. "What the students are learning is to design based on the needs of other people and users."

"The importance of observing real users is that it acquiring knowledge through empiricism," says Dan Wong, one of Hannon's senior human factors engineers. "One could postulate that people use a product in a certain way or that a certain design feature will make the product better, but why guess when you can check?"

In this case, the users are high-school and grade-school students whose teachers are using SAM as a teaching tool in the classroom. To use SAM, students mount a digital camera on a flexible arm focused downward on a table-top scene created on a white board, usually with paper cutouts and drawn with dry-erase markers. In each frame, the user moves the pieces a bit or slightly redraws the background and then takes the next photo—think claymation movies like Wallace and Gromit. Then students use SAM software to run the still frames together as a movie.

The SAM animation software was initially inspired by the son of Chris Rogers, mechanical engineering professor and Director of the Center for Engineering Educational Outreach (CEEO). Professor Rogers developed an early version of SAM to help his eldest son, Peter, create a stop-action movie for a more interactive book report. Engineering students Theo Brower (EG'06) and Ethan Searl (E'08) worked to make SAM into a more robust system.

Like Rogers, Brian Gravel, a Tufts alumnus and current doctoral student in Tufts Math, Science, Technology Engineering Education program, saw SAM's potential as a learning tool. "I noticed that the animations children made demonstrated really sophisticated and rich ideas about science that written language and even oral language struggled to emulate," says Gravel.

One of the early adopters of the SAM software is Bill Church, a high-school physics teacher in Littleton, New Hampshire. Church uses SAM with his students, who in turn are helping younger, grade-school students learn about topics such as planetary motion and cell division.

Professors of the Practice

Tufts engineer John Sison, E'09 (background) watches how Littleton High School students, Rachel, Katelynn, and Keiffer, use SAM software to create a stop-action movie about planetary motion. Human Factors engineers like John learn how to collect empirical data to design a better user experience.

Since the program's launch, SAM has gone through a multitude of iterations. Now, with the help of Dan Hannon's students, Rogers, Gravel, and teachers like Church, the SAM team hopes to further refine the program and the physical set up to be more intuitive, more-user friendly and more effective. And refinement is based on usability testing.

"Testing is done with real users, not with ourselves. We need to test on people who don't necessarily have the same vested interest in our design," says Hannon, "We may be wrong. We may have overlooked something completely fundamental"—such as a young user's fine motor skills to manipulate the SAM set up.

"For example," says John Sison, an engineering psychology senior, "one of the problems that SAM has is that the whiteboard that you use to draw stuff on moves around a lot."

Currently, if students accidentally knock the whiteboard out of place or if they move the board closer to redraw the next frame, the next photo they take may be noticeably out of alignment when the movie is played. "The purpose of this frame, called a 90° registration system, is to hold the whiteboard steady, but to allow it to quickly and accurately be returned to its previous position," says Wong. The engineering students designed a plastic frame that holds the whiteboard steady while kids move the objects on the board or draw a new background. By evaluating the situation, the team came up with this new, simple human factors solution.

The CEEO's Ethan Danahy also knows that when working with kids, the more stable and durable the equipment or tools, the better. "The students, what they want to do first thing is to grab the camera and move it around" to make the movie, often causing the plastic frame holding the camera to snap, or the arm holding the camera to lose its grip on the table.

"In engineering psychology, we ask the questions: 'What materials do we need?' and 'What properties do they need to have?'" says Hannon. The human factors students evaluated these problems and came up with two solutions. By replacing the current camera arm with more flexible, segmented tubing, the camera can be mounted in a multitude of positions without fear of breaking or coming detached. Another student, Andy Fraser, also designed a more robust holster for the camera so that it's more rigid and durable.

"User feedback will be valuable to my students," says Hannon. "They're going to make their observations and watch intently to understand how they are using the product: 'I saw Rachel do this and I saw Kate ask this; that must mean we need to change X, Y, and Z.'"

Church's students will also gather engineering psychology data when they teach lessons with SAM to their 3rd and 6th graders. "It's a neat opportunity. My students are co-investigators on the project," Church says.

"This is the kind of exposure we really like to have because human factors is very interactive. To be able to see the demonstrations, see people actively doing physical things and yet taking the time to sit and talk about it is the foundation of the field," says Hannon. "We want potential students to understand as a field of study, you get to do all this great interdisciplinary stuff. Engineering psychology by itself is interdisciplinary and then it goes beyond that to education; we can go in so many different directions."

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Story by Julia C. Keller, Communications Manager at Tufts School of Engineering

This story originally ran on Mar. 26, 2009.