Problem-Based Learning in Photonics Education

Judy Donnelly, column editor, jdonnelly@lasertechonline.org

“Your graduates know plenty of technical facts, but they don’t know how to use them to solve problems they face on the job.”

“Can’t you do something to teach these kids to write and speak effectively?”

“Why don’t your graduates know how to keep detailed records?”

Comments like these are all too common when industry advisory committees meet with college engineering and technology faculty. Part of the problem is that traditional instructor-centered teaching methods – lectures supplemented by back-of-chapter problems and cookbook laboratories with little opportunity for creative thought – do not adequately prepare students for the challenge of today’s industrial world.

Educators have developed a number of teaching methods to address industry’s need for highly skilled graduates who are competent problem solvers and communicators. One such approach is problem-based learning (PBL), a method where students learn and practice the process of solving problems at the same time they are learning course content. PBL has been used extensively since the late 1960s in medical education; it has undergone many variations to meet the needs of students at different levels and in different disciplines – for example, the case study teaching method pioneered at Harvard Business School is a variation of PBL. But no matter how and where it is used, central to the PBL approach is the emphasis on developing critical thinking skills to collaboratively solve real-world problems.

Although the details vary, most PBL methods involve solving problems in four steps: problem analysis, independent research, brainstorming discussion and solution testing. The first step is the most critical and one that students often overlook: determining exactly what the problem is, what constraints apply and what the solution requires. For students accustomed to grabbing a calculator and punching numbers into preprogrammed equations, problem analysis can be quite a challenge. Working in teams adds another layer of difficulty, as it requires thoughtful listening, discussion and compromise.

Once students have successfully defined the problem and determined what they already know and what they still need to learn, they must develop their own learning goals and timelines and figure out how to fairly split up the work. In a traditional classroom, this is the job of the instructor (“Problems 1-10 are due on Tuesday”), but in PBL it becomes the students’ responsibility. The instructor’s role in PBL is quite different from the traditional lecturing “sage on the stage.” While students seek their own resources, the instructor acts as a facilitator or consultant, circulating through the classroom, asking questions to keep students on track and providing targeted instruction as needed. Students who find logarithms boring in math class are anxious to learn about them when they need to figure out the dB loss in a fiber optic lighting system.

Once the independent learning is complete, the student team reconvenes to brainstorm possible solutions and choose the most promising. Finally, the team must test the chosen solution by showing how it meets each of the requirements defined in the analysis phase. Of course, if it doesn’t meet requirements, the cycle must be repeated until a successful solution is found. Students then present their solution, formally or informally, for what can be brutally honest peer review and comment.

The New England Board of Higher Education (NEBHE) in Boston has promoted PBL in high school and college classrooms since 2006, with grant support from the National Science Foundation’s Advanced Technological Education program. The first NEBHE PBL project, PHOTON PBL, was a natural outgrowth of NEBHE’s earlier NSF projects. From 1995 through 2006, the NEBHE team developed materials for photonics education including a textbook, a laboratory kit with experiment manual and online instructional videos, and a web-based hands-on professional development course called Introduction to Photonics. High school teachers and college faculty from across the US were trained in the use of the materials, forming a strong mentoring network of optics/photonics educators who are still in contact today through an email listserv run by industry professionals.

As the photonics projects progressed, the NEBHE team realized that addressing the process of teaching and learning is as important as developing materials for classroom use. Project PHOTON PBL (2006-2009) was designed to meet the need for instructional materials that address the way students learn best while promoting the critical thinking and problem-solving skills they need to be productive workers and lifelong learners.

PHOTON PBL worked closely with industry and research university partners to identify problems that served as the basis for eight web-based multimedia Challenges. The problems are open-ended with several possible solutions, interdisciplinary in nature, and address one or more topics usually covered in an introductory optics/photonics course. The problems also have been solved by the partner organization so students can compare and contrast their own solutions. The comparison is often eye-opening for students who naturally assume the more technology, the better. This is often the first time they are faced with the reality of cost, time and even ethical considerations. For example, the team that designed a high-tech vision system to inspect laser-stripped copper wire was surprised to learn that it was completely unnecessary for this product and far too costly to implement.

Each Challenge comprises five short videos with associated resources: “Introduction,” to set the context for the problem; “Organization Overview,” an introduction to the real people and the organization that solved the problem; “Problem Statement,” a reenactment of the presentation of the problem, for example at a staff meeting; “Brainstorming,” further discussion by organization personnel providing additional hints for students, and the “Organization’s Solution.” The last two sections are password-protected to allow the instructor to control access. While a teacher may lead novice problem solvers through all five videos in one class period, more experienced students may be required to work on their own for several days before viewing the brainstorming hints.

The “actors” in the videos are the actual engineers, scientists and technicians who solved the problem. The PHOTON PBL team visited each partner organization for a one-day production meeting that included a tour of the facility, recorded on video to provide students with a look at the environment where the problem was solved. The technical staff reenacted the phases of problem solving, and the videos clearly show them referring to their laboratory notebooks, reinforcing the importance of recordkeeping and communication skills. Representatives of partner organizations also helped to locate additional resources for students to use in the solution of the problem and reviewed the draft Challenge for technical accuracy.

Of course, neither students nor teachers can be plunged into a totally different classroom environment without preparation, so the PHOTON PBL team created extensive resources for both groups. Students raised on back-of-the-chapter problems can be intimidated by their first encounter with ill-structured, open-ended problems. The “Problem Solving Toolbox” included in each Challenge gives beginning problem solvers a place to start and a road map to follow. This document walks students through the four steps of problem solving, prompting them with questions to sharpen their critical thinking skills. The online version is known as the Whiteboards, since they can be projected onto a classroom whiteboard for whole-class problem solving. Students quickly learn the value of an organized approach and often request a copy of the Whiteboards to use in other courses. One student was overheard telling another, “You really should use this Whiteboard method. It takes more time, but it really helps you organize your thoughts so you don’t miss anything.”

Support for instructors began with a weeklong Introduction to PBL workshop that was also attended by some of the industry partners. Each Challenge features built-in password-protected instructor resources, including detailed technical information on the organization’s solution. For teachers used to grading problem-based tests, assessing student performance in PBL can be a puzzle, so suggestions and rubrics are included for assessing content knowledge (facts), problem-solving ability (a written reflection report), conceptual knowledge (relationships between concepts) and teamwork.

Teachers participating in the PHOTON PBL project field-tested the eight Challenges in their own classrooms to introduce new topics in optics/photonics, as supplemental instruction and even for after-school or other extracurricular activities. Most teachers reported that students were at first frustrated or confused, but as they gained experience, their confidence grew and they were genuinely engaged in the process. As students completed additional Challenges, they became more proficient in solving open-ended problems. One student said, “After we did the Challenges, it helped a lot. … Before that, I wouldn’t really know where to begin. … I’d probably start with, like, ‘This is my idea’ and then go check it … instead of actually going through your knowledge and going through the steps. … I would have probably wasted a lot of time.”

Challenge partners who responded to a survey from the PBL project evaluator were enthusiastic about the project and their own contributions toward promoting problem-solving abilities in their future workforce. “Collaborating with … PBL is an investment in the future,” according to one survey respondent. “As these students complete their education and enter the workforce, their ability to critically think and solve real-world problems will be an asset for any company.”

PBL Challenges

The NEBHE PHOTON and STEM PBL projects worked with 14 partner organizations including large and small manufacturing companies, research universities, and government and nonprofit organizations to create the online multimedia Challenges. The NEBHE team visited each organization to record a reenactment of the problem and its solution. The team is seeking six partners for a new grant awarded in September 2012, Problem Based Learning in Advanced Manufacturing. All the Challenges are available at www.pblprojects.org.

Project PHOTON PBL (2006-09)

• “Blinded by the Light”: What dangers does a pilot face when an aircraft is targeted by a laser pointer? The International Laser Display Association promotes laser pointer safety.

• “Stripping with Light, Fantastic!”: PhotoMachining Inc. needs to develop a process for stripping the coating from 50-µm wire.

• “DNA Microarray Fabrication”: Boston University graduate students need to determine the best starting exposure time for a DNA microarray fabricator.

• “High Power Laser Burn-In Test”: IPG Photonics needs a way to run 100-hour unattended burn-in tests on a 2-kW laser.

• “Shining Light on Infant Jaundice”: Partners Photodigm, Drexel and Southern Methodist University ask, “Can technology provide a safe and effective portable home treatment for newborn jaundice?”

• “Watt’s my Light?”: The package says a 26-W compact fluorescent has the same light output as a 100-W incandescent. Can Cal Poly Pomona students verify this statement?

• “Of Mice and Penn”: Can optics provide a noncontact measurement method as part of a UPenn McKay Orthopaedic Research Lab project to study the healing of tendons?

• “Hiking 911”: Two boys are lost in deep woods in rough terrain. Penn State Electro Optics Center (EOC) needs to recommend the best technology to locate them.

STEM PBL for Sustainable Technology (2009-12)

• FloDesign has designed a new high-speed wind turbine. Join a team of university students tasked with developing a new method to extract electrical energy from a wind turbine.

• “Johnson and Johnson”: In this PBL Challenge, you will be part of a team developing an effective new treatment for eczema using plant-derived active ingredients.

• RSL Fiber Systems is designing an ergonomic and energy-efficient lighting system for submarines.

• “SPG Solar/City of Tucson”: The city of Tucson, Ariz., wants SPG Solar to put a solar array on a large building, but the roof is not strong enough to support a traditional panel array.

• “Cape Cod Cranberry Growers Association”: Can technology be used to make an old cranberry bog more energy-efficient?

• “TTF Watershed Partnership”: Can the problem of urban stormwater be addressed by local communities without investing in huge infrastructure projects?