One Story, Different Classes: Using the Same Case Study for Different Levels of Chemistry Students Ann Taylor, Wabash College Abstract: Many of the situations, problems, and content discussed in case studies are appropriate for multiple levels of students. In many cases, the same setup “story” can be used for beginning, advanced, and non‐major students, while varying the questions and expected sophistication for the answers. Learning outcomes can be used to guide the development of the question section of the case study, allowing the case to be accessible to different levels of students. Examples of the same case being used for majors and non‐majors, cell biology and biochemistry, and large and small classes will be used, and suggestions for tailoring published cases to another course will be presented.
Article “I need a break.” Professor Anita Case put down her pile of papers to grade and picked up the TV remote. The news was on, and the lead story was an absolutely fascinating application of her field of interest. “Wow, this would make a great case study! But which class should I use it for?” Luckily for Anita, she doesn’t necessarily have to choose. A good case study tells a story, is current and relevant, creates empathy, is short, requires solving a problem, and serves a pedagogical function (Herreid, 1998). Notice that the first three qualities are completely independent of the content of the case and can be relevant for multiple audiences. Furthermore, the dilemmas that cases present often can be approached from multiple levels or even disciplinary fields. Consequently, it is possible to use the same story to present materials to different audiences by tweaking the questions the students address during the case study. The process of writing a case for multiple levels is the same as writing any case (Herreid, 1999). After deciding on a topic, brainstorming leads to possible principles that could be learned through this topic and possible characters (both real and fictional) that could star in the case Next, a compelling story, written from the perspective of characters that are in the middle of the situation can be drafted. The subsequent step is the key to writing a case for multiple levels: determining the learning objectives for the case. Most simply stated, learning objectives are what you expect a student to learn from the case (Suskie 2009). These objectives include not only the course content, but also process skills, such as interpreting graphs or discussing material with peers, and attitude development such as awareness of connections between the field of study and real world applications. These process and attitudinal objectives are often common to all versions of a case. Learning goals should be concrete enough to be measurable, yet not so narrow that they’re limiting (Suskie 2009). They are based on bringing a student from what they currently know to the expectations of the class, and both interactions with peers and guiding questions can help facilitate this growth (Chaiklin, 2003). Consequently, no two classes will have exactly the same learning goals (even when using the same case), as the students have different background knowledge and are at different developmental stages. Furthermore, different fields have different perspectives on the same topic. For example, the consideration of protein synthesis in an organic chemistry class would include goals of understanding the use of protecting groups and the mechanism of the reaction, whereas a biochemistry class might consider how enzymes facilitate the catalysis of the reaction or provide specificity. An example of how one case can be used with two different sets of learning objectives can be seen with “One headache after another” (Taylor and Cliff, 2009). While the introductory story is the same, the Biochemistry directed case questions emphasize buffer definitions, Hess’s Law, and LeChatlier’s Principle (which should be review for the students) while the Physiology version emphasizes the roles of respiratory and renal physiology and carbonic anhydrase in acid‐base balance: Biochemistry learning objectives Physiology learning objectives Recall the definition of a buffer and the Recall and use buffer system definitions, Henderson Hasselbalch equation. Henderson Hasselbalch equation, and titration curves, in reference to carbonic Predict the changes in [H+] in the blood when acid and bicarbonate. different components of the bicarbonate buffer Use Hess’s law to adjust the pKa of carbonic system are altered. acid. Describe the role of the kidney in acid‐base Use LeChatlier’s principle to predict how balance and explain the cellular mechanisms physiological responses will alter the blood whereby the kidney regulates the concentration pH by shifting the equilibrium of the of bicarbonate and nonvolatile acids in the blood.
bicarbonate buffer system. Distinguish between the transport processes responsible for bicarbonate reabsorption and for H+ secretion and reaction of H+ with buffers in the urine. Describe the respiratory mechanism that compensates for metabolic acidosis. Compare and contrast the different causes for metabolic acidosis. Explain the effect of exercise on acid‐base balance. The much longer list of expectations for the physiology class reflects both the placement in the course and the expected sophistication of the learner. Buffers are one of the very first topics discussed in a typical Biochemistry course, so the case allows students to review material from prerequisite courses in a new context and emphasizes the connections between Biochemistry and prior Chemistry coursework. In contrast, acid/base balance occurs much later in the physiology course, and draws upon student understanding of carbonic anhydrase, respiration, and renal function. (It’s possible for the biochemistry version to also be used as an example of enzyme inhibition and drug design if it was used later in the semester; indeed, I have gone back to the case as an example in homework and small group problems.) It is also important to consider your audience when constructing the learning objectives, story, and questions. What are your students’ previous experiences with the topic, either formally through classes or informally in daily life? How aware are they of current issues? What topics do they want to talk about? Depending on the size of your classes, you can find out this information either formally or informally. Finally, the student culture of the institution can give perspective on topics students need to learn about. For example, the students in my biochemistry class are often very interested in medically related topics, but are woefully unaware of health and diet issues in the media. They have diverse biology experience, ranging from nine courses in the last four years to none since ninth grade. And while their chemistry experience is more homogenous (4‐6 previous courses), there are great disparities in recall and confidence in these content areas. Consequently, my learning objectives for this class include making sure students understand fundamental concepts from previous courses as well as the applications to the case topic. The students in my non‐majors chemistry class come from a similar academic culture, but have significantly less familiarity with scientific vocabulary, so the learning objectives include more basic comprehension of the words and concepts involved in the case. An awareness of the background, vocabulary and interest can help shape a case study for multiple classes. For example, “The Case of the Shady Shells” was written for use in both a biochemistry class and a non‐majors chemistry class. While both groups read the same setup story and were sent to the primary literature, the performance expectations for the two groups were based upon their familiarity with molecular biology and enzymology skills. Consequently, while both classes answered similar introductory level questions, the biochemistry version challenged students to apply prior course concepts and use higher levels of Bloom’s taxonomy, while the non‐majors version emphasized comprehension of the main concepts. One way audiences can differ is sheerly size. There is a limit to how many small groups an instructor can assist in a typical small group format. To address this issue, a number of cases have been adapted for large group settings through using clicker response systems. For example, “Chemical Eric” is available in both a small group format (Ribbens, 2006) and as a clicker case (Ribbens, 2010). While the story line stays the same, the multiple choice questions help focus student attention on possible answers while providing good distractors to help debate in the small groups. The combined PowerPoint/Clicker combination also allows for mini‐lecture breaks during a case as well as opportunities to assess student opinions (Davis and Rice, 2009; Armstrong et al 2009). These principles of identifying your learning objectives and understanding your audience are important principles for adopting cases to any class. While published cases have been vetted for their content, the instructor will need to tailor the content and delivery method to most appropriately meet the needs for his or her class. Call for comments How have you adapted case studies for use in different courses? Do you use learning objectives to help guide development of your case studies? What audience factors do you consider in designing a case, and how do you accommodate these concerns? References Norris Armstrong, Terry Platt, and Peggy Brickman (2009) The Case of the Druid Dracula: Clicker Case. http://sciencecases.lib.buffalo.edu/cs/collection/detail.asp?case_id=493&id=493 accessed 3/28/11 Seth Chaiklin (2003) The zone of proximal development in Vygotsky’s analysis of learning and instruction, in Vygotsky’s educational theory and practice in cultural context, ed. Kozulin, Gindis, Ageyev, Miller. Cambridge University Press. Cheryl Davis and Nancy Rice (2009) Another Can of Bull? Do energy drinks really provide a source of energy? http://sciencecases.lib.buffalo.edu/cs/collection/detail.asp?case_id=506&id=506 Merle Heidemann and Gerald Urquhart (2005) A Can of Bull: do Energy Drinks really provide a source of energy? http://sciencecases.lib.buffalo.edu/cs/collection/detail.asp?case_id=203&id=203, accessed 3/25/11 Clyde Herreid (1999) Cooking with Betty Crocker: A recipe for case writing. JCST 29 (3), 156‐
158, available at http://sciencecases.lib.buffalo.edu/cs/pdfs/Cooking%20With%20Betty%20Crocker‐XXIX‐3.pdf, accessed 3/25/11. Clyde Herreid (1998) “What Makes a Good Case?” JCST, pp. 163‐165. Eric Ribbens (2006) Chemical Eric: Dealing with the Disintegration of Central Control, http://sciencecases.lib.buffalo.edu/cs/files/chemical_eric.pdf. Accessed 3/28/11 Eric Ribbens (2010) Chemical Eric—The Clicker Version: A Case About the complexity of Hormonal Control http://sciencecases.lib.buffalo.edu/cs/collection/detail.asp?case_id=503&id=503 Accessed 3/28/11 Linda Suskie 2009. Developing Learning Goals (Ch 8), in Assessing student learning: A common sense guide (2nd Ed.). San Francisco: Jossey‐Bass. . Ann T.S. Taylor and William Cliff (2009) One headache after another. http://www.sciencecases.org/topiramate/notes.asp accessed 3/28/11