Practicing the Scientific Method
Lesson 6 of 12
Objective: SWBAT practice the scientific method as they carry out an investigation.
What are the steps in the scientific method?
Giving students an opportunity to practice using the steps of the scientific method increases their knowledge, ability, and confidence when performing scientific experiments. Asking questions, defining problems, carrying out investigations, analyzing data, and communicating information are at the core of the NGSS Science and Engineering Practices. This is an important practice when teaching students to implement the Scientific Method. Taking time to teach this skill will benefit the learner throughout the year. Practice is a thinking activity and it takes times to make meaning of it.
I want students to review the Steps in the Scientific Method, so I provide a worksheet with a chart so they can fill in the steps. This provides an outline for their thinking. Over the years, I have learned that as middle school students learn these steps, they need an abbreviated version to begin to understand the process. These 6 steps provide an easy, systematic method for them to understand how to carry out investigations.
Teacher Tip: Have students write Bell Ringer answers in their Science Journal. This not only saves paper but it keeps their thoughts, questions, ideas, and drawings in one place.
Using the Scientific Method
A major practice in science is to carry out investigations (Practice 3 Planning and Carrying Out Investigations). For students to learn how to do this, I have them write the steps, implement the steps, and then reflect on the process. This can be done with any experiment, but I choose one that was interesting and fun for middle school students, a Chromatography Lab. This experiment is quick and easy to complete in one class period and it helps students understand the process.
In this lesson, I use structured inquiry because students need to be lead through an investigation to: learn and understand the steps of the scientific method, learn new vocabulary words such as hypothesis, conclusion, and data, and learn how to reflect on the data to create a well-written conclusion.
I go through the directions with the class, provide the question, and help students form an hypothesis. I read the directions aloud while students also read them silently. I do this because my students are at a variety of reading levels. As students write their hypothesis, give them time to process. This is when I would circulate the classroom to make sure they have the right idea. Taking time to share a few written hypotheses will give students confidence that they are "on the right track." A sentence stem is provided for each hypothesis: I think that .........because ........ The hypothesis should reflect what the question is asking. I tell students to "put the question into the answer." This step can be broken down further by dividing the statement into two pieces so a student can work on one at a time. For example: I think that.... I know this because...
I circulate the classroom to make sure that all students are on target, have written an hypothesis and are ready to more forward. Using "popsicle sticks" to draw all students into the discussion, I ask students to read and share their hypothesis. This gives students an opportunity to hear the thoughts of their classmates. As a class, we continue to read through the investigation and perform the steps together. This helps to solidify the understanding of the process.
Now, perform the experiment. I communicate with students to make clear, thoughtful observations and use the Data Table to record the results. When students analyze and interpret data they are connecting to Science and Engineering Practice 4. They need to carefully examine the date to answer the questions which will lead to forming a conclusion.
Teacher Tip: Try this Candy Chromatography experiment as an extension activity or use permanent markers and isopropyl alcohol in place of the washable markers and filter paper.
Write a Conclusion
Now, let's write a conclusion. As with any experiment, sometimes it works and sometimes it doesn't, but that ok. This provides opportunity to discuss what went right, what went wrong, and changes that could be made to the experiment. This step is very important for students to "come full circle."
I have learned that you need to take students back to the question so they can think about the process. Is the color you see on the tip of a marker its real color? Take 1-2 minutes for students to process this question and write a conclusion. I give them a sentence starter to help with the process, for example: I learned that . . .because. . . Take 1-2 minutes to share answers with the class so students can hear other student thoughts.