Case Types & Teaching Methods: A Classification Scheme
This type of case (also sometimes called an issues case) is used to teach students skills of analysis. The material is focused around answering questions like, “What is going on here?” An analysis case frequently lacks a central character and generally stops short of demanding that students make a decision. Examples would be a description of the Valdez oil spill, a collection of papers and data showing the possible effects of vitamin C on the common cold, or a selection of articles arguing whether the HIV virus is the causative agent of AIDS. Examples in our collection include The Deforestation of the Amazon and The Wolf, the Moose, and the Fir Tree.
A dilemma (or decision) case presents an individual, institution, or community faced with a problem that must be solved. It often consists of a short paragraph or section that introduces the problem (and the decision-maker) at the moment of crisis. A background section fills in information necessary to understand the situation. A narrative section then describes recent developments leading up to the crisis. Charts, tables, graphs, letters, or other documentation that helps lay the foundation for a solution may be integrated into the case or appended. The teacher's goal is to help students sift through the facts, analyze the problem, and consider possible solutions and their likely consequences. Examples include: As Light Meets Matter and Life on Mars.
A directed case is designed primarily to enhance students’ understanding of fundamental concepts, principles, and facts. The case usually consists of a short, dramatic scenario accompanied by a set of “directed” questions that can be answered from the textbook or lecture. The questions are “closed-ended” (i.e., typically they have only one correct answer). Students prepare answers to the questions, which they provide in class when called upon during the case discussion. Questions usually are assigned as homework, with students working individually or in groups to prepare their answers in advance, although instructors may have students prepare answers in class, again either individually or in groups. An example is A Friend in Need is a Friend Indeed. Read more: Cliff, W.H., & L. Nesbitt Curtin, 2000, “The Directed Case Method,” Journal of College Science Teaching 30(1): 64-66.
This type of case presents a problem for students to solve in a progressive disclosure format, with the case given to students in parts to work on in small groups and complete within a single class period. A common method for developing an interrupted case is to take a scientific paper and choose a research question from it (or have students read the paper’s introduction and work in groups to pose a research question based on the issues it raises). Students develop hypotheses and design experiments to test them, which they then present for the class to critique, after which the instructor gives students information on how the actual authors of the paper tackled the problem. After a description of the authors’ methods, students are asked to predict the results, which they report on when called on in class. The instructor then reveals the actual data, which students interpret. The instructor brings closure to the case by revealing the authors’ interpretations and conclusions. This format allows students to practice the scientific method – from question formulation to hypothesis testing, experimental design, and data analysis and interpretation. For examples, see the cases: Mom Always Liked You Best and Why Sex is Good. Read more: Camill, P., 2000, “Using Journal Articles in an Environmental Biology Course,” Journal of College Science Teaching 30(1): 38-43.
Clicker cases combine the use of student personal response systems (“clickers”) with case teaching methods and formats. The case is presented in class using a series of PowerPoint slides in parts, or stages. After each stage, students are asked to respond to questions (called “clicker questions”) posed by the instructor. In this way, students work their way through the material to understand (and also usually solve) the problem presented in the case. Specifically designed for use in large introductory science classes, the method integrates lecture material, case storylines, student discussion, (clicker) questions, clarification of the answers to those questions, more lecture, and data. Examples of clicker cases include: Cross-Dressing or Crossing-Over? and An End to Ulcers? Read more: Herreid, C.F., 2006, “’Clicker’ Cases,” Journal of College Science Teaching 36(2): 43-47.
Laboratory-based cases or cases with a lab component place laboratory experiments in a setting that make them both more relevant and engaging for students. Many require that students design a laboratory approach that can be used to solve the problem. A well designed lab case typically (1) tells a story that is interesting and relevant to students, (2) poses a challenging problem for students to solve experimentally, (3) allows students to work in teams to design their own approach to solving the experimental problem, with minimal guidance from the instructor, and (4) requires a report written in a narrative format. Examples of cases that are lab-based or have a lab component include: Filthy Lucre and Burning Down the House. Read more: Dinan, F., 2005, “Laboratory-Based Case Studies,” Journal of College Science Teaching 35(2): 27-29.
Problem-Based Learning (PBL)
PBL is a teaching method in which students work cooperatively in small groups to find solutions to problems. The focus is on having students identify the learning issues associated with a problem themselves. The case is given out piecemeal, typically over several class periods. In the classical form, small groups of students (usually 4-8) meet with a tutor (facilitator) to solve the problem, which they are introduced to through a short narrative (or research paper, video clip, etc.). Together they try to identify the broad nature of the problem (the learning issues), defining what they know as well as what they do not know and need to find out. They then divide up the list of questions they have generated and search for answers. At a second meeting, students pool their findings in their groups and try to resolve the problems identified earlier. At this point, the tutor may provide additional information (test results, experiments, new data, etc.). Students refine the problem, divide up the workload, and adjourn to collect more information. At a third meeting, information is pooled and often a report is written. Examples include: A Typical Cold and AIDS and the Duesberg Phenomenon.
The discussion method for teaching a case has long been used by business and law schools. Students are usually presented with decision or analysis cases. The instructor's job is to identify with the students’ help the problems, possible solutions, and consequences. On the surface, the method is simple: the instructor asks probing questions and students analyze the problem. The instructor may question students using a strong directive (and iterative) approach, often called the Socratic Method. Others may use a nondirective approach to class discussion, staying on the sidelines and acting more as a facilitator while the students take over the analysis. Seasoned case discussion teachers advocate directive but not dominating questioning, good blackboard work to highlight the essential issues, and a summary at the end to bring closure to the case. Examples of cases taught in the classic discussion method include: “Bad Blood”: A Case Study of the Tuskegee Syphilis Project and A Case Study of Memory Loss in Mice.
A debate format is well suited for many types of cases where two diametrically opposed views are evident. A good format for the debate is to follow the procedure of moot court competition. Two teams of students each prepare written briefs on both sides of the issue and are prepared to argue either side. Just before the debate, they flip a coin to see which side they must argue. The debate itself starts with the pro side presenting for a prescribed period of time, usually 5 minutes. Then a person representing the con side speaks for 5 minutes. There is a 5-minute rebuttal by a second speaker on the pro side, followed by a 5-minute rebuttal on the con side. This is then followed by 3-minute summaries by each side. In a classroom setting where some members of the class are not participating in the debate, it is valuable to permit questions from the audience and ask them to evaluate the content and presentation of the debate. An example of a debate case is Oak Clearcutting: To Cut or Not to Cut?
Intimate debate is a powerful technique for dealing with case topics that involve controversy. Basically, two pairs of students face off across a small table, arguing first one side and then switching to argue the other side. At the end of the exercise, they must abandon their artificial positions and try to come to a consensus as to what is a reasonable solution to the problem being debated. The advantages to the approach as contrasted with formal debate include: time efficiency (multiple intimate debates can take place simultaneously); dispassionate scrutiny (switching positions tends to reduce initial “buy-in” or commitment to a given side of the issue); greater participation by the reticent (because there is no audience); and increased realism (the call for consensus opinion mimics real-world policy making where decisions must be made within given time frames and with (possibly) insufficient information). Examples of intimate debate cases include The Medicinal Use of Marijuana and Golden Rice.
A public hearing format for a case study is another way to explore differing viewpoints on a topic. Public hearings are structured so that a student panel, role-playing as a hearing board, listens to presentations by different student groups. Typically, the hearing board (EPA, FDA, etc.) establishes the rules of the hearing at the outset (e.g., time to speak, order of presenters, rules of conduct, regulations and criteria governing their decision-making). This is followed by individuals or groups role-playing particular positions. Members of the panel often ask follow-up questions of the presenters. After the presentations are completed, the panel makes its decision or recommendation. Teachers using this method may find that the public hearing approach works most effectively over more than one class period. Alternatives to having the students prepare the testimony include using the transcript of an actual public hearing or a script developed by the instructor for a particular scenario, which the students then role-play. Examples of cases taught in this way include: To Boldy Go ... or Not? and Too Many Deer!
A case may include a mock trial. This may be done informally or formally. In a more formal trial format, there would be two opposing sides, each represented by an attorney with witnesses and cross-examination. The trial would begin after a brief introduction by the instructor, after which the attorneys for the two sides take over. The interests of the first side are presented by its attorney and (a maximum of say three) witnesses, with each witness alloted a set time (say 3 minutes) followed by 2-minute responses during cross-examination by the opposing attorney. Then the opposing side’s attorney and witnesses take the stand. The trial proceeds with each side alternating their witnesses and cross-examination. Finally, the attorneys for each side sum up their positions in 3 minutes. To ensure that the student audience remains engaged, prior to the trial you might have students work in teams to develop two short (2-page) position papers, one favoring one side and the other the other side listing the key arguments on each side, which students turn in at the time of the trial. You can also have all of the students write 2-minute reaction papers after the exercise, which can be collected as they leave class. An example of a case that includes a mock trial is: The Plan: Ethics and Physician-Assisted Suicide.
A technique used in teaching a case study, jig-saw enhances cooperative learning by making each student responsible for learning, and then teaching, a portion of the case material to his or her group. The method is simple in principle. The instructor has students working in groups. Each group is given a specific piece of the problem to study (in many cases, this may be from a particular viewpoint). They become experts in that part of the problem. Meanwhile, other groups are working on other parts of the puzzle and becoming experts themselves. Each group only sees the part they are focusing on. Finally, when the time is right, the teacher asks the class to reassemble in new arrangements. One person is drawn from each group and put together into new groups. In this way, you end up with “experts” from different groups sitting together, where they pool their information to form a complete picture (and usually also produce a product, such as an analysis of the problem or a solution to it, a position paper, etc.). Cases that employ jig-sawing include: Genetic Testing and Breast Cancer as well as Are You Blue? What Can You Do?
With role playing, the students assume (and may even act out) a role (possibly a role they would not normally occupy) in order to understand that role or the situations those occupying that role must deal with. This is often done in terms of adopting the role of a stakeholder in an issue in order to understand that particular person's or constituency's point of view. Examples of case studies that use role playing as a component of the case include: Closing the Gap: Antiretroviral Therapy for the Developing World and How a Cancer Trial Ended in Betrayal.