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An End to Ulcers?

A Case Study in the Scientific Method

Co Authors:

Kristina Hannam
Department of Biology
SUNY Geneseo

Rodney Hagley
Department of Biology and Marine Biology
University of North Carolina-Wilmington


This “clicker case” teaches students about the scientific method by following the story of the discovery of the cause of human gastric ulcers by two Australian biomedical scientists. Students see how the researchers followed up an unusual observation by applying the steps of the scientific method in support of their new hypothesis for the cause of this disease. Students practice the scientific method themselves by proposing their own hypotheses, identifying methods for testing the hypotheses, and predicting the results of experimental tests. Developed for a large introductory biology course, this case could also be used in an undergraduate microbiology course for pre-nursing majors to introduce the contemporary theory that many chronic medical conditions have an infectious origin. The case consists of a PowerPoint presentation (2.5MB) shown in class that is punctuated by multiple-choice questions students answer using personal response systems (“clickers”). It could be adapted for use without these technologies.

  • Construct a hypothesis based on reported observations.
  • Develop a prediction based on a hypothesis.
  • Identify appropriate methods (including controls) for testing a hypothesis.
  • Examine data and draw conclusions about whether or not they support a hypothesis.
  • Develop an understanding of how prevailing ideas in science are modified.
  • Apply the scientific method using a real life situation.
Keywords: Hypothesis; prediction; experiment; experimental design; ulcers; peptic ulcer disease; bacteria; bacterial disease; Helicobacter pylori; J. Robin Warren; Barry J. Marshall; Nobel Prize in Physiology or Medicine 2005
Topical Area: History of science, Scientific method
Educational Level: High school, Undergraduate lower division
Formats: PDF, PowerPoint
Type/Method: Clicker, Interrupted
Language: English
Subject Headings: Biology (General)   Microbiology   Science (General)   Medicine (General)  
Date Posted: 10/10/08
Date Modified: N/A
Copyright: Copyright held by the National Center for Case Study Teaching in Science, University at Buffalo, State University of New York. Please see our usage guidelines, which outline our policy concerning permissible reproduction of this work.

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