Germ Theory for Middle School Science Teachers

Table Of Contents

Turning Points in Science: Germ Theory

Introduction

Background Information for Teachers

Lessons on the Historical Context

Lessons on the Germ Theory in the 21st Century

National Science Education Standards

Latest Version

Introduction

This is the first publication in our series called Turning Points in Science, which highlights the history and nature of science. The second publication covers the topic of Copernican revolution and the third, atomic theory.

The most exciting phrase to hear in science, the one that heralds the most discoveries, is not "Eureka!" (I found it!) but "That's funny." — Isaac Asimov

In 1989 the American Association for the Advancement of Science (AAAS) published Science for All Americans, which states,

. . . science education — meaning education in science, mathematics, and technology — should help students to develop the understandings and habits of mind they need to become compassionate human beings able to think for themselves and to face life head on. It should equip them also to participate thoughtfully with fellow citizens in building and protecting a society that is open, decent, and vital.

In 1996 the National Science Education Standards (NSES) was published, heavily influenced by Science for All Americans. For example, Science for All Americans contains chapters titled The Nature of Science and Historical Perspectives. You may be aware that the content standards of NSES include a domain title History and Nature of Science.

This publication, Turning Points in Science: Germ Theory, is the first in a series focused on historic, pivotal scientific advances, such as the discovery of germs, the Copernican model of the universe, and the elucidation of atomic theory. To avoid the pitfall of isolating the history and nature of science from science content, this series will focus on a specific advance relevant to the NSES content standards in life, physical, and earth sciences by examining the context of the science as thoroughly as possible. In this way, the science becomes understandable as a human endeavor; thus its impact on society is easily conceived. A potentially useful tool will be James Burke's Knowledge Web, which provides the connections between historic figures in science that enabled the advancement of science. Although a video explaining the tool is in Beta version only at the time of this writing, users can view it and bookmark the site for future use.

This publication also aims to facilitate student mastery of the Science as Inquiry standards. As students become aware of the methods of science, some unique to the various science disciplines, they will notice the unity in the use of logical argumentation based on empirical evidence. Researchers' personal accounts of their discoveries often fail to tightly align with the misnomer "the scientific method," and yet their findings have endured. Thus, we examine the status of the scientific concepts of interest at the point in history when the researchers’ findings joined the discussion: Who had made what claims, how, and why? What were the strengths and weaknesses of these claims? What were the competing hypotheses?

Middle school students’ conceptual understanding often recapitulates the history of science; their initial conceptions of natural phenomena are naive conceptions — explanations conjured up to account for their own experience with nature. For example, students often claim that aluminum foil is a good insulator because they have seen it used to wrap cans of pop in an attempt to keep the cans cold. The history of humanity shows similar kinds of misconceptions. For instance, the sun went around the earth, obviously; it rose every morning in the east and set every evening in the west. As another example of historic misconceptions, people thought necrotic tissue caused sickness. It was not conceivable that a nonvisible organism caused the sickness that resulted in necrotic tissue. Teachers can use student naive conceptions as a starting point.

This publication focuses on the elucidation of the germ theory of disease. This theory represents the culmination of the work of several individuals across time. Resources provided here will facilitate understanding of the early scientific community's concept of disease; the thinking that led to hypotheses relating germs to disease; the various observations and experiments that yielded information allowing for theorizing; the scientific community's reaction to and acceptance of the early investigators' findings; and the impacts of the theory on humanity.

In the Background Information for Teachers, resources include research articles on student naive conceptions and how to conduct inquiry teaching, a video description of the nature of scientific theory, followed by some history-related resources about important contributors to the germ theory of disease and their experiments. The two sections with lessons and activities are meant to facilitate student understanding of the context, the emergence, and the impact of the germ theory of disease. All of the resources touch on the NSES standards for History and Nature of Science, Science in Personal and Social Perspectives, Life Science, and Science as Inquiry. A very old, but accurate dramatization, The Story of Louis Pasteur is worth viewing by teachers. After viewing it yourself, you may consider encouraging your students to view it as enrichment.

An additional resource you may find helpful to use with your students is a book published by National Geographic Children's Books, Killing Germs, Saving Lives: The Quest for the First Vaccines. This title was selected by the National Science Teachers Association as one of the 2007 Outstanding Science Trade Books for Students K–12. The book, illustrated with prints and photographs, is told from a historical perspective and presents the work of scientists and healthcare providers who have observed, experimented, and accidentally discovered vaccines. The book demonstrates people’s changing ideas about diseases and the time needed for new discoveries. It also mentions ongoing efforts to find new vaccines. Check your local or school library or order a copy at the National Geographic Online Store.

by Mary LeFever

Mary LeFever is a resource specialist for the Middle School Portal, and a doctoral candidate in science education at Ohio State University. She has taught middle school and high school science and is an adjunct instructor of biology and natural sciences at Columbus State Community College. Please email any comments to msp@msteacher.org.

There's More! You'll know when new science publications are posted on NSDL Middle School Portal by requesting free email notices at http://msteacher.org/registration.aspx. Don't forget to browse the Science Pathway every once in a while to find a wealth of resources for your teaching.

Blog with Us. Every week, we connect what's making the news to the National Content Standards...so you can too! Read and share your ideas on our blog Connecting the News to National Science Education Standards at http://expertvoices.nsdl.org/connectingnews/.

Copyright November 2007 — The Ohio State University. This material is based upon work supported by the National Science Foundation under Grant No. 0424671. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation.

This work is licensed under a Creative Commons License.