Lesson Plan: The Process of Scientific Experimentation
Overview
To find the answers to scientific questions, scientists may use an organized set of procedures typically referred to in textbooks as the "scientific method" of experimentation. Often described as a tidy, step-by-step process, the scientific method is in reality less linear. Procedures are refined as data are collected and initial hypotheses modified or replaced in light of new evidence. In this lesson, students begin by addressing the question, "What is the scientific method of experimentation"? They engage in group discussions followed by a full class discussion based on what they think. Next, they watch video accounts of actual scientific research and re-examine their ideas considering what they see. Citing evidence from the videos, the groups present their findings to the rest of the class. Finally, following an expanded discussion on the processes of science, students collaborate on a better-informed description of the scientific method.
Objectives
* Examine the traditional textbook description of the "scientific method" of experimentation
* Recognize that scientific investigations begin with questions that arise, for example, from observations, unexpected results, and the research findings of others
* Understand that answering a question about the natural world, such as how stem cell therapy might be used to treat a range of genetic conditions or bodily injuries, often involves experimental setup and critical analysis, and that theories, though they may be improved on, are well supported by data
* Recognize that scientific knowledge can be constructed in some disciplines, including Earth science and evolutionary biology, without reliance on experimentation
Grade Level:9-12
Suggested Time:Two class periods
Media Resources
Note: The list features media-rich resources with life science, physical science, and Earth and space science content.
Key:
* LS = Life Science resource
* PS = Physical Science resource
* ESS = Earth and Space Science resource
* Evolving Ideas: How Does Evolution Really Work? QuickTime Video (LS)
* Toxic Newts QuickTime Video (LS)
* The Red Queen QuickTime Video (LS)
* Stem Cells Breakthrough QuickTime Video (LS)
* Galileo: Sunspots QuickTime Video (PS/ESS)
* Synthesizing an Alkaloid QuickTime Video (PS/LS)
* Synthesizing a Steroid QuickTime Video (PS/LS)
Materials
* Computers, each equipped with an Internet connection
* Science notebooks
Before the Lesson
* Arrange three or more viewing areas in the classroom, assigning a computer with an Internet connection, if available, to each.
* Familiarize yourself with each of the videos to be shown.
The Lesson
Part I: The "Scientific Method"
1. Begin with a discussion about the term "scientific method." Ask students to describe the scientific method based on what they have been taught, read in textbooks, or experienced. Have them work in small groups and come up with a group description. Have each group then share its ideas with the class. For example, students might suggest that the scientific method is a step-by-step process that begins with a hypothesis and serves to "prove" that hypothesis?an understanding that may be consistent with a "textbook" definition but one they should ultimately discover may be flawed. While science can easily disprove a hypothesis by presenting counter evidence, it cannot prove one. Rather, it can only support a hypothesis, given current evidence. Summarize and record these initial ideas so that you can return to the list for revision later in the lesson.
2. Prepare students to test their understanding of scientific processes. Divide the class into smaller viewing groups and explain that each group will be assigned to view a case of scientific discovery from the list of media-rich resources. (Note: The list features media-rich resources with life science, physical science, and Earth and space science content.) If your access to technology resources allows it, have each of the groups watch its assigned video in a different area of the classroom. If this is not possible, you may choose to present the videos to select to the entire class or rotate the groups so that each watches only its assigned video.
3. After viewing its assigned video, have each group identify two or more specific examples from the video that either support or refute its earlier description. To help students organize their evidence, it may be useful to have them watch the video again and look for specified information. For example:
1. What motivated the scientist(s) to investigate a question?
2. What ideas did the scientist(s) begin with?
3. Did the scientist(s) make a prediction before gathering evidence?
4. What evidence did the scientist(s) gather?
5. What procedure did the scientist(s) follow?
Part II: Case Studies
4. Using evidence from its video, each group will summarize for the class how well its depiction of scientific processes conformed to its initial description of the scientific method. Have each group compare and contrast the two processes?the one it generated in Part I and the one it saw in practice in the video case study. For example:
1. Did the scientist(s) start with a hypothesis, or was it a question?
2. How did they test their ideas, and what did they measure?
3. Did they use a control?
4. Did experimental results confirm their initial hypotheses, or did they have to modify their thinking on a subject?
5. Where did a scientist's unique inferences about observed phenomena determine the direction of the process?
6. What steps, if any, were not apparent in the videos?
5. Groups should emphasize any differences between their understanding of how science gets done and the way it is presented in the videos.
6. After each group summarizes its findings, have it present the video it watched to the entire class, suggesting questions for the other students to consider as they watch.
Part III: Group Discussion
7. See if you can draw out some important points about scientific inquiry and investigation that are not typically part of textbook treatments. Be sure to insist that students use evidence from the videos to support their views. Here are some questions and ideas you might ask them to address:
1. What do you think drives scientists to perform their work? A list based on the videos in this lesson might include curiosity, personal history, and academic achievement.
2. Scientific experiments rarely go without a hitch. Do you think science has to be so "messy"? Why or why not?
3. History shows that external factors, including racial and religious climate and economic concerns, influence how science gets done. What factors today determine the kinds of things that are and are not investigated? Do you think science can operate outside the reach of politics and corporations? Be sure to provide reasons to support your ideas.
4. When we say "science is a public process," what do we mean? How is peer review designed to work? Based on the cases you are familiar with, does it work?
Check for Understanding
Gather the groups together for a final class discussion. Based on the videos and subsequent class discussion, ask students whether their original descriptions of the scientific method need to be changed. If so, in what significant ways? Write a revised description on the board that reflects the class's new, more complete understanding of scientific processes.