Case Study Teaching in Science

Center for Teaching at Learning,UTB/TSC

Tamara K. Pease, Ph.D.Dept of Chemistry and Environmental Science

Great Teachers Are Often Great Storytellers

• Cases are stories with a message; stories to educate.• Not narratives for entertainment. • Cases gives a teacher an immediate advantage– the attention of the audience.

History of Using Stories for Teaching

• Oral history • Aesop’s Fables, Aristotle, fairy tales• storytelling as an education tool began in law and business

courses– law and business schools realistic stories as exemplars of

good and bad practice. • medical schools in the “grand rounds”

Case Studies are Self-Contained Stories

• In its original form– largely self-contained stories – analyzed through the discussion method in the

classroom

Do Case Studies Work?152 faculty surveyed:• 97% -- students learned new ways to think about an issue• 95% -- students took a more active part in the learning

process• 92% -- students were more engaged in classes• 84% -- students were glad case studies were being used• 59% --students were more likely to do independent research

outside the classroom to improve their understanding of the material

• 68%-- students learned more in classes using case studies

• National Center for Case Study Teaching in Science

Ways To Tell The “Story”

• Lecture method• Whole class discussion• Small groups• Individual case instruction• Mixed method

Lecture method

• Richard Eakin (UC Berkley) dressed as famous scientists (Darwin, Mendel, and Pasteur) to lecture as if these scientists actually visited the classroom.

• Chemist James Conant (Harvard) developed an entire course in science centered on great discoveries (Harvard Case Histories in Experimental Science) .

Acting out a story improves the lecture method.

Whole Class Discussion Method • Variant of the Socratic method

– ask the student to paraphrase the argument, – the teacher then asks whether the student agrees with the argument– the teacher trys to force the student to defend his or her position by

rebutting arguments against it.• Interaction between a student and the professor,

– other students listening– occasional student-student involvement

• Many variations– cases that unfold in the form of role playing, debates, trials, and public

hearings, • all within the framework the whole class

Characteristics of a Good Discussion Case

• Be short. 1-3 pgs., something that can be covered in a single class– but can extend for several weeks or even over an entire semester

• Pose a dilemma/are controversial. – care must be taken to maintain careful analysis

• students can be swept up with controversy• competitive nature of the discussion rather than giving the topic

careful analysis.• have dialogue makes the cases appear more real• have interesting characters.• be relevant to the student.

Discussion includes role-playing and debates

Characteristics of a Good Discussion Case

• Have a dilemma to be solved– Results in involvement in the outcome of the discussion– must take a positio.

• Be contemporary– students greatly prefer timely topics (in the news)

• Be real rather than fabricated– hard to get involved in a generic case,– a fantasy case (e.g., involving Spiderman) does capture interest

• Have learning objectives and lessons that can be generalized to other situations.

Discussion includes role-playing and debates

Discussion Case: Open vs. Closed CasesCases may or may not have a right or wrong answer

Closed Cases:• Have right and wrong answers. • Premium on facts, principles, and definitions. • Medical school cases

– patient has a complaint, the correct diagnosis is essential, • Lower end of Bloom’s taxonomy of knowledge.

Discussion Case: Open vs. Closed CasesCases may or may not have a right or wrong answer

Open:• Several plausible solutions

– “reasonable people can differ” • Student must sift through the facts, evaluate them, and weigh the possible

options and consequences of the decision• Business school cases are open• “Should the United States sign the Kyoto treaty?”

– clearly has people on different sides • High end of Bloom’s taxonomy of knowledge

– synthesis, analysis, and evaluation

Small groups - Problem Based LearningCases sharpen student analytical skills and teamwork

• McMaster University’s Medical School– First day some details about a patient’s symptoms.

• Separate out the things they knew and those they didn’t. • Seek information from texts or the Internet to assist in their

deliberations. – Second Day pool their information and again determine what was or

was not known. • Receive additional information (e.g., clinical test results or a new

complication)• Reanalyze the situation and seek more information.

– Finalize their diagnosis and receive their next case. • Increased analytical skills• Increased teamwork skills• Increased independent learning

Small Groups -- Problem Based Learning (PBL)

• PBL may require heavy investment of faculty time• Modified PBL

– unifying feature• cases begin with problems to be solved• not all of the information is given at once.

Small Groups – The Interrupted CaseStudents can be given cases in stages

• Favorite method of many science faculty • Variation of PBL• Uses progressive disclosure of information rather than giving away the

entire story line at the outset. – Differ from PBL the case is accomplished in a single class

• Receiving information piecemeal mimics how scientists analyze problems. • Provides obvious structure to the discussion

– An important point for those students and faculty who not comfortable with freewheeling conversation.

Small Groups – The Jigsaw ApproachStudents can be asked to arrive at a consensus

• Groups are given different pieces of information and asked to come to a consensus about a problem– Each group may represent a different stakeholder.

• Example overfishing near the Galápagos Islands. – When the government of Ecuador clamped down on illegal

activity, bands of fishermen took over the Charles Darwin Research Station and held the scientists hostage. » Set up different groups to represent the scientists,

fishermen, tourists, shop owners, and politicians. • Set up new groups

– One representative from the former groups responsible for hammering out a compromise policy

Individual Case InstructionA student may analyze both sides of an issue

• Cases in a tutorial setting or by individual assignment • Dialogue case

– student writes a short play about a controversial subject• write a verbal exchange that might take place on this topic

between intelligent, informed people on opposite sides of the question.

• write at least 20 comments and responses for each protagonist.– comments must be substantial, not frivolous

• at the end of the paper write own opinion along with a reference section.

– students often change sides after this task

Mixed methods Students may be asked to find solutions to questions about a case

• Many hybrid approaches• Direct case method

– common in Anatomy and Physiology courses, coverage of material is critical

– case is often one or two paragraphs that outline a patient’s symptoms, e.g., high blood pressure.• followed by a series of questions. • work individually over days to find answer• instructor gives a series of traditional lectures on the subject.

– end of unit, one class period is set aside to deal with the questions;• instructor collects the student papers and then runs a discussion

of the topic

Strengths and Weaknesses of MethodsTeachers should have a clear goal of what is to be accomplished

• Lecture cases are still lectures – have the same limitations as any other lecture – may be more fascinating as stories but listener is passive

• Discussion cases with the whole class– students are often reluctant to speak out – a few individuals may dominate the discussion– in large classes only a few individuals can contribute– faculty have limited experience leading good discussions

Small Group Cases Are the Most Popular

• May be easiest cases to teach for faculty used to the lecture method– do not demand the questioning and listening skills

• Case given to small groups to analyze– team representative can reports on the group’s deliberations. – faculty can comment– groups of five people is ideal

• still participate• if they don’t prepare, is evident

A Case-Study I Use

The Effects of Coyote Removal in Texas:A Case Study in Conservation BiologybyMargaret CarrollDepartment of BiologyFramingham State College

Figure 1

Figure 1. Location of experimental sites in West Texas. Sites 1 and 2 were the control sites. Coyotes were removed from sites 3 and 4 and from a 5-km border (figure from Henke and Bryant 1999, used with permission).

Figure 2

Figure 2. Relative abundance of mammalian mesopredators in the experimental sites before and after treatment. Error Bars represent one standard error (figure modified from Henke and Bryant 1999, used with permission).

Figure 3

Figure 3. Biomass of rodents in the experimental sites before and after coyotes were removed from the treatment sites. Error Bars represent one standard error (figure modified from Henke and Bryant 1999, used with permission).

Figure 4

Figure 4. Diversity of rodents in the experimental sites before and after coyotes were removed from the treatment sites. Rodent diversity was estimated using Simpson's Index. Error Bars represent one standard error (figure modified from Henke and Bryant 1999, used with permission).

Barriers to the Case Method Novelty is worrisome and risky

Faculty barriers• It takes time to convert your course• Content coverage

– cannot cover as much material as with lectures• most students forget much of the information

• Control is an issue with some instructors– who knows what the students will say?

• May not know how to run a discussion– what do you do when no one talks?

• Don’t want to give up center stage. • May not feel teaching is as effective. • What happens to teaching evaluations• How do you know if students are truly learning?

Barriers to the Case Method Novelty is worrisome and risky

• Student barriers – like the familiar.

• used to the lecture method and know how to cope with it.– confusion

• they don’t know what will happen even if you tell them that the results will be better.

– threatening to the pre-professional health students and honors students • already do rather well with lecture method.

Barriers to the case method Novelty is worrisome and risky

• Colleague and administrative barriers– don’t care unless there is a problem, then may have an opinion/get

into the act• Parent barriers

– if new method of instruction puts their child at a disadvantage, – controversial topic such as evolution or sex education

Finding Published Cases

• Journal of College Science Teaching -- regular column dealing and it publishes an annual issue devoted to case studies.

• Several journals routinely publish articles with cases or assessing the method.

• University at Buffalo (http://ublib.buffalo.edu/libraries/projects/cases/case.html)

• University of Delaware(https://chico.nss.udel.edu/Pbl/)

Some Useful References

• Herreid, C. F. 1994. Case studies in science: A novel method for science education. Journal of College Science Teaching 23 (4): 221-229.

• Herreid, C. F. 1998. Sorting potatoes for Miss Bonner. Journal of College Science Teaching 27 (4): 236-239.

• Herreid, C. F. 1997. What makes a good case? Journal of College Science Teaching 27 (3):163-165.

• Cliff, W. H., and L. M. Nesbitt. 2005. An open or shut case? Journal of College Science Teaching 34 (4): 14-17.

• Glew, R. H. 2003. The problem with problem-based medical school education: Promises not kept. Biochemistry and Molecular Biology Education 31: 52-56.

• Herreid, C. F. 2003. The death of problem-based learning? Journal of College Science Teaching 32 (6): 364-66.

• Herreid, C. F. 1995. “Mother always liked you best”: Examining the hypothesis of parental favoritism. http://ublib.buffalo.edu/libraries/projects/cases/coots/coots_prologue.html (accessed May 5, 2005)

Some Useful References• Herreid, C. F. 2000. Jigsaw: A case study technique where students become

experts. http://ublib.buffalo.edu/libraries/projects/cases/teaching/jigsaw.html (accessed May 5, 2005)

• Herreid, C. F. 1999. Dialogues as case studies: A discussion on human cloning. Journal of College Science Teaching 29: 245-249.

• Cliff, W. H., and A. W. Wright. 1996. Directed case study method for teaching human anatomy and physiology. Advances in Physiology Education 15: Sl9-S28.

• Cliff, W. H., and L. Nesbitt Curtin. 2000. The directed case method. Journal of College Science Teaching 30(1): 64-66.

• Hudson, J. N., and P. Buckley. 2004. An evaluation of case-based teaching: Evidence for continuing benefit and realization of aims. Advances in Physiological Education 28: 15-22.

• Birx, J., and J. Foster, 1993. The importance of lecture in general chemistry course performance. Journal of Chemical Education 70: 180-182.

• Johnson, D. W., and R. T. Johnson. 1989. Cooperation and competition: Theory and research. Edina (MN): Interaction Book Co.

Some Useful References

• Johnson, D. W., and R. T. Johnson. 1993. Cooperative learning: Where we have been, where we are going. Cooperative Learning and Teaching Newsletter 3(2): 6-9.

• Herreid, C. F. 1998. Why isn’t cooperative learning used to teach science? BioScience 48: 553-559.

• Herreid, C. F. 2004. Why a case-based course failed: An analysis of an ill-fated experiment. Journal of College Science Teaching 33 (3): 8-11.

• Dochy, F., M. Segers, P. Van den Bossche, and D. Gijbels. 2003. Effects of problem-based learning: A meta-analysis. Learning and Instruction 13: 533-568.