Reinforce the utility of scientific investigation through realistic scenarios that require students to team up and think like experts.
Associate Professor of Chemistry, Spelman College
PhD in Physical Chemistry, BS in Textile Chemistry
Dr. Lisa Hibbard teaches General Chemistry for Majors at Spelman College, a historically black women’s college in Atlanta. “All declared chemistry or biochemistry majors are required to take this course,” says Hibbard. “These are chemistry majors. They want to learn the basics so they can keep moving through the curriculum.” This may mean that they expect the course to be skimming the surface of science—or they might think it will simply review concepts they have already covered in high school. More likely than not, they will expect to be immersed in the textbook, memorizing definitions and equations and breezing through short-answer and multiple-choice tests. Hibbard wants them to immerse themselves, to be sure—but not just in intangibles and theories.
Instead, she wants her students to really connect with the material and see how these foundations actually matter in the world. “Students sometimes get lost in studying the fundamental concepts; they don’t see the applications,” she explains. “I try to make chemistry real for them. I want them to understand that the ideas we are discussing in a particular chapter—gas laws, or calculation of the molar mass of a particular compound—are things that people use on a daily basis. I want to bring the material to life.”
Innovation: Solving real-world mysteries with chemistry concepts
To address the challenges her class faces, Hibbard divides students into groups of three or four and asks them to apply textbook chemistry concepts to real-life scenarios (aka cases or case studies). In short, she turns each student into “Sherlock the Chemist,” asking the groups to analyze a case and propose a “chemist’s solution” to the pragmatic problems that it poses.
“The use of case studies is fairly rare in chemistry,” Hibbard allows. But the National Center for Case Study Teaching in Science at the State University of New York at Buffalo actively promotes the method. Obviously, so does Hibbard, who is one of the department’s most senior professors. In fact, she has authored and coauthored several papers on her active learning methods, including the use of case studies.
Hibbard's Active Learning Articles
Here, Hibbard shares some of her writings and presentations on active learning, specifically related to flipped approaches in chemistry courses.
In reality, some of Hibbard’s cases prove to be quite dramatic: They range from controversial scenarios taken from recent media to mundane problems of everyday living. For example, students may study the 2010 Children’s Tylenol recall that was precipitated by a change in dosing recommendations. Here students are dealing with unit conversions, such as milliliters (mL) to teaspoons and grams to milligrams (mg), and using information to determine maximum dosage based on body weight. Or they may consider why a blowout might happen if a car’s tires are filled with too much air. “In this case, the group must do an analysis of why air pressure in a tire may change with the temperature,” Hibbard explains. “That’s a practical application of [the] gas laws [that] they need to know, and it is based on [an] experience an incoming freshman may actually have had.”
Hibbard adds that this approach “can help a student with limited life experience understand why she is studying chemistry in the first place. That can engage her in a way that a bunch of algorithmic problem-solving in class might not.”
“I want students to know that there are real-world applications for the scientific concepts they learn in this introductory course.”— Lisa Hibbard, PhD
Frequency: Four 50-minute class meetings per week for 15 weeks in a semester
Class size: 30–35
Course description: As the first course in the General Chemistry sequence for majors, students will be introduced to the basic principles of modern chemistry. The student will learn methods of scientific experimentation that will lead to the development of chemical principles used in practical problem-solving. Topics to be covered include measurement, atomic theory, nomenclature, stoichiometry, chemical reactions, gas laws, thermochemistry, electronic structure, periodic properties, and an introduction to chemical bonding.
See resources shared by Lisa Hibbard, PhDSee materials
Lesson: Solving problems by thinking like a chemist
Hibbard generally assigns four cases in the fall semester and two in the spring, including one comprehensive case involving a major written assignment.
The written assignment involves turning in a group-authored research paper, modeled after a scientific journal article, that reflects the group’s investigation of a specific topic. They must also submit a written proposal for how to resolve the issue using scientific techniques from their textbook. Later in the second semester, each group is also required to create a case themselves, such as “The Case of the Sleepless Student.”
Here are some of the strategies Hibbard employs to help students achieve these benchmarks:
Link cases to specific textbook concepts
Most of the cases Hibbard’s students work on are designed to reinforce specific ideas from the syllabus. In one instance—entitled “Am I Poisoning My Child?”—students work on a case over a period spanning both semesters, and the case incorporates ideas from multiple units.
This case requires students to think critically about a media claim that commercial apple juice can contain arsenic, as well as the subsequent concern that this report raised among consumers regarding the potential toxicity of the beverage. (Arsenic, the students will learn, occurs in both toxic and nontoxic forms.) One of the related tasks is to draw the two arsenic-containing compounds that might be found in the juice. To do this, students use a type of diagram called a Lewis structure.
Mix individual and group contributions
The “Sleepless Student” case, which is based on issues raised by a segment of Dr. Mehmet Oz’s popular television show, requires students to do pre-case exercises as individuals before coming together as a group to work on the case itself. “In the fall, they’re working on their own as they learn the relevant concepts,” says Hibbard. “Most pre-case activities require students to visit relevant websites where they can do some research on the case topic. Some of the websites are readily accessible and are visited regularly by the public (e.g., news media, YouTube videos, Consumer Reports) while others are more geared towards scientists and health professionals (e.g., WebMD, National Institute of Standards and Technology).”
By the spring semester (in the second half of the course), students will use these earlier findings to generate solutions to the problems posed by the case study. “By this point, they will be working in groups,” she says. This is helpful because no two minds work quite the same way, so they open themselves up to a wider range of ideas by coming at the problems together. “The case analysis forces students to learn to work with their peers: That’s a soft skill that employers want in new hires,” Hibbard points out.
Example: “The Case of the Sleepless Student”
Hibbard has authored most of the case studies that she has been using for the past several years, but one of her favorites—“The Case of the Sleepless Student”—was adapted from a case created by her students five years ago. Here is the scenario it presents:
A female student is sitting in a break room at a coed dorm, late at night, having a conversation with a male peer. She complains that she has not been sleeping well. The male student offers her pills to help her sleep; he assures her that he got them from his brother, and they are safe. Having taken the drug, she passes out as she and her new “friend” are walking out the door. Campus police investigate; they accuse the male student of drugging the young woman deliberately.
The case write-up provides Hibbard’s students with bloodwork that identifies the chemical components of the drug. The students must determine what the drug is, using legitimate research principles that they study in a chapter on formula calculation. “They go online and find out the compound is a common date rape drug,” Hibbard explains. “Then they have to evaluate the question of the male student’s responsibility: Should he be arrested?”
“Our students adopt the persona of a lab technician at the hospital who is doing the drug analysis,” Hibbard explains. “Unfortunately, it’s a highly relevant scenario for young women. But also, a lot of our students come into the major hoping to have careers in health professions. This is something that they could potentially face in the health profession down the line.”
Flip the classroom in multiple ways
“Seven years ago, I revised the sequence [of General Chemistry for Majors] so that the course is taught using a flipped learning format,” says Hibbard. “My narrated lectures are posted on our learning management system (Moodle), with the entire semester’s course materials. Students are required to prepare for class.” This includes prep work for case studies, with students doing the research together outside of class time.
Push students to think like experts
The case study exercise asks students to use the scientific background they acquire over two semesters, render an opinion, and back it up with scientific facts. For example, in the narrative of the arsenic case, a mother listens to the media discussion about arsenic and apple juice, and she concludes that the product is unsafe for her children. Is she a responsible mom playing it safe, or is she overreacting to irresponsible speculation on television?
Using this kind of critical judgment is essential, not just for scientists but for everyone. And yet, this exercise may be the first experience students will have in applying that kind of judgment, Hibbard suggests.
Encourage students to consult experts
To take students beyond what they can learn online or from the textbook, Hibbard’s cases often ask students to talk directly to scientific authorities. For example, students may interview on-campus experts from the Spelman faculty, such as toxicologists in the Department of Chemistry and Biochemistry, or professors from other departments. “I want students to get to know people from other disciplines, to see that chemistry is not a stand-alone science,” Hibbard explains. “Cases frequently are cross-disciplinary scenarios.”
Let students create their own content
Hibbard feels it is crucial for new people coming into research fields to be able to communicate effectively about science to a lay audience—hence the requirement for groups to write their own cases, following a detailed rubric. This takes place well after students have been exposed to the cases Hibbard has developed.
“I allow them to pick a topic involving a concept they’ve learned in either the first or second semester, and write their own case,” she says. “That’s a second-semester project that improves their writing skills.”
Assign students to assess each other
Team members are asked to assess one another’s work, following a rubric for assessment that Hibbard provides.
She notes that it is not always the A students who get the most out of the case studies. “They’re the students who are the most excited about chemistry—the ones who are the most captivated by the way the science works in the real world,” she says.
This approach may be more challenging with larger classes, she allows. “When I taught classes of 100, it was harder to incorporate team-based learning approaches,” says Hibbard. “I’m lucky to have smaller classes now and [to] have the opportunity to do more innovative things.”
At the end of the semester, students are asked to respond to the following question in their course evaluations: “Identify a particular book, reading, or activity that you really liked or disliked. Explain why.”
The response to her case studies was largely positive, though some students felt that they required too much time, outside research, and prior knowledge of chemistry. Others had this to say:
“I liked the case studies because I was able to apply the topics learned from each chapter to a real-life situation.”
“I like doing the case studies. It shows how you can apply the material to real life.”
“I liked the case studies. They encouraged me to think outside the box and apply all I have learned in class.”
“[I] thoroughly enjoyed being in a ‘team’ for the whole semester so that we could work through [case studies] together and have people to rely on outside of the course.”