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CHAPTER 3
Strategies for Teaching the Scientific Method and Its Components

What Is It?

The scientific method and its components are the backbone of all sciences, so it is emphasized in nearly every science curriculum. The most detailed version of the scientific method includes the seven steps listed here. Many educators teach students all seven steps; however, some prefer to combine steps 5 and 6.

  1. Ask a question.
  2. Perform research.
  3. Write a hypothesis.
  4. Set up and perform an experiment.
  5. Analyze results.
  6. Write a conclusion.
  7. Publish results.

The scientific method is used when a question can be answered through data collection via an experiment. If a question can't be answered with an experiment but, instead, requires additional research or observation, then the inquiry process is used. See Chapter 4: Strategies for Teaching the Inquiry Process for resources to teach this process. If a question can be answered through the design of a new technology or process, then it's more appropriate to use the engineering process, which is discussed in Chapter 6: Strategies for Teaching the Engineering Process.

Why We Like It

The scientific method is used to learn many topics, including some that go beyond the field of science. Its purpose is to organize information to solve problems in a manner that minimizes bias and prejudice (Harris, n.d.). The scientific method's basic components (asking a question, creating a hypothesis, testing the hypothesis, and drawing a conclusion) are not limited to science classrooms. Examples include students solving math problems through trial and error, performing historical research, and writing research reports.

Students who know how to use the scientific method are better prepared for future science classes and are more likely to perform well on college entrance exams that include science concepts, such as the ACT and SAT Subject Tests (ACT, 2019, p. 8). The ACT includes a science component that requires students to have basic knowledge in biology, chemistry, earth/space sciences, and physics, and emphasizes aspects of the scientific method such as analyzing and evaluating data. There are SAT Subject Tests for biology, chemistry, and physics. The three exams test a student's ability to organize and analyze data, draw conclusions, and make inferences, all of which are steps in the scientific method (College Board, n.d.).

Supporting Research

Research shows that students who participate in active learning, including the use of the scientific method, tend to outperform their peers who are taught using traditional lecture-based learning. These studies indicate that when students are taught science through active learning, failure rates can decrease significantly, while test performance increases (Wieman, 2014, p. 8319).

In addition, using hands-on learning through the scientific method has been shown to increase motivation and learning in science (Dhanapal & Shan, 2014, pp. 34–38).

The scientific method can also be used to teach scientific literacy, the ability to ask and answer questions about everyday life, describe and predict natural phenomena, read and understand scientific articles, participate in arguments regarding the validity of conclusions, and analyze data validity and reliability based on how it was obtained (National Research Council, 1996, p. 22).

By learning the scientific method, students are practicing many skills that increase their scientific literacy, such as asking questions, reading scientific articles for research, describing observations after experimentation, and identifying errors in experimental designs to determine if data is valid and reliable.

Skills for Intentional Scholars/NGSS Connections

All three Skills for Intentional Scholars are practiced while students use the scientific method. For example, students are using critical thinking skills when performing research and writing their hypotheses. They are creatively problem solving while designing experiments. And, students are effectively communicating during the data analysis and conclusion steps.

Components of the scientific method are integrated throughout the Science and Engineering Practices and Crosscutting Concepts that are intertwined in Next Generation Science Standards (NGSS) (National Research Council, 2012, p. 85). The NGSS advise science teachers to integrate required science content, the scientific method, the inquiry process, and the seven crosscutting concepts into their lessons (NGSS, 2013c, p.3). The activities in this chapter will include several of these requirements.

Application

In this section, we walk through the seven steps of the scientific method and provide specific activities that can be used in any experimental situation. Depending on the age of the students, it has been our experience that teaching these seven steps requires three to four 1-hour instructional periods, in addition to the time needed to perform the experiment. Since we don't always know how much experience high school students may already have using the scientific method, we include an activity to assess their background knowledge later in the chapter.

We begin teaching the scientific method by explaining that it is the process used in many authentic science labs and out in the field. It is used by many scientists such as biologists, oceanographers, physicists, chemists, and engineers.

When we first introduce the scientific method in class, we describe its step-by-step process. Obviously, less scaffolding is required after students become more familiar with the steps.

STEP 1: ASK A QUESTION

We begin by explaining that the scientific method starts with a question because it provides the focus for a scientist's research and experimentation. The question keeps scientists focused and prevents them from steering off topic.

Often, we generate the question and not our students. This is because we want all students focused on a specific concept. There are times when it's appropriate to have students generate questions, which is discussed in Chapter 4: Strategies for Teaching the Inquiry Process.

To generate experimental questions, we begin with the content we want students to learn. Table 3.1 depicts five examples of how we connect content to the first step of the scientific method: Ask a Question.

Table 3.1 Connecting Content with Experimental Questions

Content being taught Question generated
Biomimicry requires scientists to understand structural and functional properties of nature How strong is human hair?
Heat denatures enzymes and enzymes break down proteins What happens when fresh pineapple is added to gelatin?
The difference between hydrophobic and hydrophilic What is the most efficient process to clean birds after an oil spill?
Osmosis is an example of diffusion, a process of passive transport What happens to gummy candy when left in water overnight?
Newton's third law of motion Why do balloons move away when the air inside is released?

When we are creating a new unit, we make a concerted effort to generate questions that can be leveraged in teaching multiple concepts. For example, after cleaning oily duck feathers to teach the difference between hydrophobic and hydrophilic liquids, the same feather experiment can be used to teach the difference between polar and nonpolar molecules or it can be used to teach the effects of water pollution on aquatic wildlife.

Students don't perform these experiments a second time, but, instead, use their data later in the school year when they are learning other content. The benefit is that this data will now function as the required background knowledge for future lessons. See Chapter 13: Strategies for Activating Prior Knowledge for resources that help students identify and use their background knowledge.

STEP 2: PERFORM RESEARCH

After we've written the scientific question, we then decide what information our students need to know so they can perform their experiment. To help students understand why it's important to do research, we explain that step 3 will require them to write a hypothesis, which includes a justification for the anticipated results of their experiment. The research they do in this step will help them justify the hypothesis they will be writing.

There are two possible methods to direct student research. One method involves teaching the content beforehand and then requiring students to research only the information that is needed to answer the experimental question. We choose this format when the science content is difficult to understand or when students have very little background knowledge. When we work with middle school students, we use the gummy candy example in Table 3.1 to teach the concept of osmosis. Students do a lab where they leave the gummy candy in water overnight. Osmosis is a new concept for many students and it's difficult to understand by simply reading about it.

Other times, we require our students to research a broader scientific concept we want them to learn, in addition to the information that is needed to answer the experimental question. We choose this format when students have some background knowledge about the topic or the topic is simple to understand. Using the Newton's third law of motion example in Table 3.1, many high school students have been exposed to Newton and his laws in previous classes. In this case, students are required to research all of the following: Newton's third law of motion, the concept of air pressure, and how balloons function.

We also take the age of our students into account when we determine what they should research. In our experience, younger students become overwhelmed if they are exploring too many topics. Given this challenge, we tend to reserve the research of multiple topics for advanced middle school and high school students.

Determining where students will find their research is another decision we make when we plan an experiment. When we work with younger students, we typically provide resources for them, such as library books or a list of websites. We often require students at the higher grades and advanced students to find the resources themselves. Students can obtain information from books, online resources, and articles. Research can also be accomplished by watching videos, performing interviews, and observing phenomena. See the Technology Connections section for student-friendly, online research resources.

We've found that students who struggle with reading comprehension may benefit from a structured note-taking process when they perform research. We use Figure 3.1: Student Research Organizer to assist these students. It requires them to document three main points from each source, which tends to increase student comprehension and retention of the material (Naidu, Briewin, & Embi, 2013, pp. 62–63).

Another benefit of using Figure 3.1 is that plagiarism tends to occur less often, but only when students fill it out by hand. When students are allowed to document their research electronically, many tend to copy-and-paste entire passages with no modifications or attributions. Additionally, having hard copies for students limits the amount of space they have to take notes because, unlike in an electronic format, the size of the boxes doesn't expand as students write. By minimizing the amount of space students have to write, students are challenged to summarize, which is an effective strategy for increasing reading comprehension (Janzen & Stoller, 1998, pp. 254–259).

One struggle we experience every year is that many students have difficulty discerning fact from fiction when they perform online research. In Chapter 4: Strategies for Teaching the Inquiry Process, we provide strategies that help students develop information literacy skills.

STEP 3: WRITE A HYPOTHESIS

We first explain that a hypothesis is a proposed outcome of an experiment that includes a justification for the proposal. For example, if a hypothesis proposes that cats always land on their feet if they fall from a minimum height of 12 in., then the hypothesis must also include the reason why cats can do so (they have advanced righting reflexes).

Before writing a hypothesis, students must first identify the independent and dependent variables. Note that some state standards refer to these variables as the manipulated and responding variables.

Prior to sixth grade, most teachers identify the variables for their students. However, starting in sixth grade, the NGSS require that students begin to independently identify the variables and controls (NGSS, 2013b, p. 1). This practice continues throughout high school as students are exposed to more complicated concepts and advanced experimental designs.

We use Figure 3.2: Identifying Independent and Dependent Variables to introduce students to the concept of variables. This worksheet requires students to become familiar with the new vocabulary terms and then teaches them the differences between the two variables. Students complete the worksheet in partners because, as we discussed in Chapter 2: Strategies for Teaching Lab Procedures, research concludes that student groups of two tend to promote better communication (University of Leicester, 2010).

The first practice problem in Figure 3.2 includes the answer, so students have a model. There are five additional practice problems and three challenge problems. Some students who struggle to remain focused during class may need shortened assignments. In this case, we only require them to complete three of the additional practice problems and one of the challenge problems.

The teacher answer key can be found in Figure 3.3: Identifying Independent and Dependent Variables—Answer Key.

Once students are familiar with identifying variables in hypothetical experiments, their next challenge is to identify the independent and dependent variables in the class experiment. For example, if the experimental question is “What happens to gummy candy when left in water overnight?,” they first need to determine that the independent variable is whether or not the candy is left in water. Then, they need to identify if the dependent variable is the mass, height, length, width, density, and/or color of the candy before and after it's placed in water.

Depending on the purpose of the lesson and the age of the students, the teacher can either dictate the dependent variable(s) or the students can choose their dependent variable(s). When using this experiment to teach about osmosis, we give our middle and high school students the option of choosing two or more dependent variables because any of the variables in this experiment will demonstrate that osmosis has or has not occurred overnight.

Once students identify their variables, they can write their hypotheses. One format for writing a hypothesis is “If…then…because…” where the if statement holds the independent variable, the then statement holds the dependent variable, and the because statement explains the research that justifies the expected results.

For those students new to writing hypotheses, we use Figure 3.4: How to Write a Hypothesis. Each student receives a copy of the worksheet, but they work together in pairs. We begin by asking for volunteers to take turns reading the directions aloud so the class can hear the definition and purpose of a hypothesis. Then we explain the format of writing a hypothesis.

We want students to understand why the scientific method requires scientists to perform research prior to writing their hypothesis. To initiate this connection, the worksheet instructs students to talk to their partners and discuss the order of performing research and writing hypotheses. As students have their discussion, we walk around the room and listen to their conversations. We may ask struggling students a guiding question, such as, “What three things are required to write a hypothesis?” Students can reference their worksheet and may answer, “The two variables and the research,” at which time we reply, “So why should the research be completed before writing the hypothesis? Why can't we write the hypothesis first and then perform the research?” Students might respond, “Because we need the research to write the hypothesis.”

Our goal in this lesson, and in most lessons, is that students use their critical thinking skills to answer the questions on their own. We try to avoid simply giving them the answers. Instead, we provide resources they can use to determine the answers, including a learning partner and a guiding question.

Once the class understands that research is a critical component of forming a hypothesis, students continue to read the worksheet. They read the two methods that will help them remember which variable goes into each part of the hypothesis. The first method involves using the letters I and D. We explain that the word independent begins with the letter I and it is I, the scientist, who determines the independent variable. The word dependent begins with the letter D and it is the Data that is collected During the experiment and recorded in a Data table. By using the first letters of the words independent and dependent, students are less likely to confuse the two.

The second method uses the definition of the two terms. Independent means that an event occurred without help from other events. Dependent means that an event occurred because of another event. After reviewing the definition of the words with students, we further explain that independent variables occur without the help of other variables, but dependent variables occur because they require the help of the independent variable. Students are instructed to choose whichever method helps them to properly differentiate between independent and dependent variables.

As a class, we go over the first problem on the worksheet. We walk the students through the example, challenging them to identify the independent and dependent variables. Once every student has documented the correct variables, we challenge them to write the hypothesis using the “If…then…because…” format.

We ask them to fill in the because statement of the hypothesis with any facts they may already know. After all, the purpose of the worksheet is to learn the format of hypothesis writing so, while completing this worksheet, it's less important what students write in the because statement.

Students are then instructed to work with their partner to complete the worksheet. Afterwards, groups of two are paired with other groups of two to compare answers. Students must then debate any differing answers to determine whose answer is correct. We provide the class with sentence starters (see Table 3.2) in order to help students build their academic vocabulary and discourse skills. Table 3.2 can be projected onto a screen or printed and distributed to students. We explain that these sentence starters are intended to begin and maintain respectful conversations.

As we mentioned earlier, some students may benefit from shortened assignments. They could be given the option of completing half of the practice problems. This modification provides students with some practice and is not as overwhelming as having to complete the entire worksheet.

After students complete Figure 3.4: How to Write a Hypothesis, we choose random students using popsicle sticks, index cards, or an online tool such as Class Dojo, to share their answers with the class. Sometimes, we are more strategic in choosing students. For example, we may practice in advance with an English language learner so he or she can develop more confidence when participating in class. Or, perhaps, we'll choose a student who has been struggling but has a good response for this assignment. Students can either read their answers or project them onto the board using a document camera. We provide students with an opportunity to ask questions after each response is revealed. The teacher answer key is found in Figure 3.5: How to Write a Hypothesis—Answer Key.

Table 3.2 Debate Sentence Starters

Agreement statements Disagreement statements
“I agree with you because…” “I like what you were thinking but I was thinking…”
“I like what you wrote here. I also wrote…” “Can you explain this answer to me because I wrote something different?”
“I agree that…” “Have you considered…?”
“We agree with each other on this question because…” “I notice…”
“You made me realize that…” “I wonder…”

Once students can identify variables and plug them into the “If…then…because…” format, they are ready to write a hypothesis for the class experiment.

We connect the experimental question, variables, and research in order to write the hypothesis. For example, in grades 7–12, an appropriate experimental question about osmosis would be, “What happens to gummy candy when left in water overnight?” A student's hypothesis could state, “If gummy candies are placed in water overnight, then their mass will increase because osmosis causes water to passively move across the candy's membrane.” Elementary students would not necessarily study osmosis but could study the movement of water in plants. If their experimental question was, “Does the color of the water affect the color of a flower?,” then their hypothesis would be, “If a white carnation plant is given colored water, then its petals will match the water's color because water moves through the plant's petals.”

Before moving to the next step of the scientific method, we require every group to turn in their hypothesis so we can review it for accuracy. The hypothesis is the experiment's backbone because it drives the experimental design, data collection, and lab report. Their hypothesis must be written correctly if they are going to be successful in the remaining steps of the lab.

If a group's hypothesis does not use the correct format, we meet with the group members and ask guiding questions so they can identify what is incorrect and how to make improvements. Research shows that if teachers want their feedback to impact learning, students must be allowed to use that input immediately to improve their work (Irons, 2010, p. 148).

After we verify that a group has written a hypothesis that follows the format, they are then free to begin setting up their experiment.

STEP 4: SET UP AND PERFORM AN EXPERIMENT

Prior to performing an experiment, we require students to complete the following:

  • Write a materials list.
  • Document the step-by-step procedures.
  • Make a list of the controls.
  • Create the data table.

We begin teaching Step 4: Set up and Perform an Experiment by explaining the purpose of identifying materials, procedures, and controls: that experiments must be completed multiple times with similar results to be considered reliable. This means that other scientists need to know precisely how the first scientist conducted the experiment so they can duplicate the experimental design.

Materials List

As students design their experiment, they need to create a materials list. This includes the materials used and the required quantity of each material. Older students typically don't struggle with this task. However, since younger students may require more structure, we provide them with Figure 3.6: Student Materials List.

Step-by-Step Procedures

Using their materials list, students then write their step-by-step procedures.

To achieve reliability in an authentic science lab, scientists perform multiple trials. According to Science Buddies, a popular online resource for science fairs, school-based experiments should have at least three trials (see Technology Connections). Students' step-by-step procedures should reflect the number of trials they will have in their experiment.

The traditional lesson plan for teaching students how to write step-by-step procedures is to have them write the directions for making a peanut butter and jelly sandwich. Although we could not determine who first created this lesson plan, we confidently assume it's popular because many students have background knowledge about how to make a peanut butter and jelly sandwich. However, with the rise in peanut allergies, we've replaced this lesson with a list of activities that students can choose from when they practice writing their procedures. Here is the list we provide our students:

  1. How to brush your teeth.
  2. How to make your bed.
  3. How to charge your cell phone.
  4. How to read a book.
  5. How to catch a football.
  6. Come up with your own idea and have it approved by your teacher.

Students first write their practice step-by-step procedures using one of the options from the above list. They then have a family member follow the procedures at home or have a fellow student follow them in class. We emphasize that the person following the procedures should literally do each step as written. Students use that person's interpretation as feedback to edit their procedures. We only ask classes to practice using non-experimental scenarios, such as the ones listed above, at the beginning of the year when the scientific method is first introduced. After this practice is complete, all future step-by-step procedures are written for authentic science experiments.

Once students have practiced writing their step-by-step procedures using something familiar to them, they then write the procedures for the class experiment. We remind students that the procedures must include any applicable lab safety requirements, everything in their materials list, and clean-up directions. Note that the lab safety rules we use are in Figure 1.1: Science Safety Contract English in Chapter 1: Strategies for Teaching Lab Safety. We tell students ahead of time that the lab's required materials will be at the lab stations on the day of the lab so they do not have to write a procedure for how and where to obtain lab materials.

Controls and Data Tables

Prior to performing an experiment, we also have our students list their controls, which sometimes are referred to as constants, and make their data table. We first explain that controls are the things that must remain the same between the experimental and control groups. To provide an example, we describe a hypothetical experiment, such as determining if plants grow taller if they are given fertilizer. We draw two pots on the board and ask students to first identify the independent variable (whether the plant receives fertilizer) and the dependent variable (how tall the plant grows). Then we explain that controls are all the characteristics that must be the same between the two pots. Students are asked to brainstorm the controls with a partner. We then hand markers to several random students and ask them to write one control on the board, around the pots. This continues until we have about 10 controls, which may include the size of the pot, the amount of soil in each pot, the amount of water given to each plant, and the species of plant.

To engage the students in critical thinking, we ask them, “Why are controls important?” They discuss this question with a partner and then share out their answers. We want students to understand that when an experiment has too few controls, there is no way of knowing if the results occurred because of the independent variable or the lack of a control. For example, did the fertilized plant grow taller because it received fertilizer or because it was watered more often than the non-fertilized plant? We can't determine what caused the plant growth because there were two differences between the two pots.

To teach students the concept of controls and how to make data tables, we use the worksheet in Figure 3.7: Finding Controls and Making Data Tables. We created this worksheet for younger students (fourth through eighth grade) but have also found it useful at the high school level because it's a good review for identifying independent and dependent variables. As we stated earlier, we provide some students with shortened assignments as a differentiation strategy. We may only require them to complete two of the four practice problems, which gives them more time to complete the assignment accurately. The answer key can be found in Figure 3.8: Finding Controls and Making Data Tables—Answer Key.

When we introduce this worksheet to our younger students, they are challenged to identify the dependent and independent variables. After a class discussion of the correct answers, we model how to use the variables to make a data table with an appropriate title and measurements, along with a list of controls. The students then work with their learning partner to complete the same tasks for the other scenarios.

Once students have completed the worksheet, we provide the correct answers and respond to any questions that arise. Some students may finish earlier than others. Those students who complete the worksheet prior to their classmates are instructed to create their own experimental scenario, identify the variables and controls, and make the data table. We encourage students to write their scenarios about something they find interesting, such as a sport, a hobby, or a musical instrument.

When using this worksheet with high school students, we model the first scenario and then allow them to answer the remaining questions independently. Students compare answers with a partner and then we review the answers as a class. During this activity, as usual, we walk around the classroom so we can assist students who require more instruction and support.

Once students are familiar with identifying controls and making data tables, we ask them to make a list of the controls in their class experiment and create a data table using their independent and dependent variables.

Performing the Experiment

Prior to performing any experiment, we tell students that their grade is not based on whether their data does or does not support their hypothesis. Instead, it is based on how they interpret their data. We tell them that when scientists obtain data they are not expecting, it indicates that they have learned something, which is the purpose of science!

Students are now finally ready to begin experimenting and collecting their data. As they perform the class experiment, we remind students to record their data in their data tables. See Chapter 2: Strategies for Teaching Lab Procedures for strategies on grouping students, monitoring for on-task behavior, and ensuring thorough clean-up after a lab is complete.

STEP 5: ANALYSIS

The analysis step of the scientific method includes making a graph and writing a Discussion of Results. We explain to students that scientists use data analysis to identify patterns and outliers, which allows them to draw conclusions.

Making a Graph

After students complete their experiment and clean their lab area, they use their data to make a graph. The NGSS require second-grade students to learn how to make bar graphs and fifth grade students must learn how to make line graphs (NGSS, 2013a, p. 2). Because it is likely that fourth and fifth grade students are familiar with bar graphs but not line graphs, we provide them with a premade graph so all they need to do is plot their data. Their premade graphs include a title, x- and y-axis titles, units of measurement, and a key, if necessary. Beginning in sixth grade, students are provided with blank graph paper and we make the graphs together as a class. In seventh grade and above, we provide students with blank graph paper, an example of a well-made graph, and a checklist, which can be found in Figure 3.9: Example and Checklist—Making Graphs.

Of course, it is a mistake to assume that all students have learned the science concepts required by the NGSS at each prior grade level. Not all states have adopted the NGSS and some students may have moved from different countries. Even if you are in a state that has adopted the NGSS, there is no guarantee that prior teachers have followed the standards in their teaching or, even if they have, that students remember what they were taught. Ultimately, we must meet students where they are and provide any needed scaffolding.

We teach a step-by-step process for making graphs, both with traditional graph paper and in Microsoft Excel. This strategy can be found in Chapter 11: Strategies for Incorporating Math, which also includes information on teaching students how to interpret data in charts and graphs.

Writing the Discussion of Results

In our experience, writing lab reports can be challenging for students. To help students of all ages, we use lab report “starters,” also known as paragraph frames. Figure 3.10: Discussion of Results guides them through the process of writing a full analysis. Students are instructed to complete the sentence starters and deepen their answers where space allows. Younger students are allowed to complete the Discussion of Results in small groups, but starting in seventh grade, we require each student to complete his/her own analysis.

We explain to students that scientists write a Discussion of Results to present the data in written form and to interpret the data's meaning, including possible experimental errors and suggested improvements for future experiments.

STEP 6: CONCLUSION

Before students write their Conclusion, we explain that scientists write Conclusions because they must now connect their hypothesis to the data they collected. Scientists use Conclusions to summarize the meaning of their data as it pertains to the hypothesis.

Students whose data didn't support their hypotheses still have valuable data. Prior to students beginning their experiments, we explain that when a scientist's data is unexpected, the scientist learned something and can use that knowledge in future experiments. We assure students that scientists often have data that doesn't support their hypotheses and it's okay for them to be in the same situation.

We've also found that many students struggle to write Conclusions, so we created Figure 3.11: Conclusion, another lab report starter that follows the same pattern as Figure 3.10: Discussion of Results. And, just as with the previous lab write-up, younger students can write their Conclusion in small groups. However, in our experience, it's appropriate to expect seventh graders and above to write their Conclusions independently (obviously, there will be exceptions to support differentiated instruction).

STEP 7: PUBLISH RESULTS

We explain to our students that Step 7: Publish Results is possibly the most important step in the scientific method. We ask them, “Can you imagine if a scientist found a cure for a disease but then never told anyone?” After a class discussion about the ramifications of not sharing scientific discoveries, we offer students options for publishing their data. They can:

  • Share their results with a parent and then obtain their parent's signature.
  • Place their lab reports in a portfolio. Some schools have student-led conferences instead of traditional parent/teacher conferences. Students create a portfolio, which is a collection of the work they feel best represents their learning. They then share the portfolio with their families.
  • Make a Prezi at www.prezi.com or a slideshow outlining their experiment and its results. Both are then published online automatically.
  • Share their lab report with another student whose class is doing the same project. We've arranged class meetings with other teachers on our campus, allowing students to share results with their peers. Students have also shared their results with other students via email or Google Drive.
  • Participate in a science fair.
  • Publish the results in a class blog and share them with a “sister class.” See the Technology Connections section for further information on this option.

DIFFERENTIATION FOR DIVERSE LEARNERS

In addition to the differentiation ideas we mentioned throughout the Application section, here are more specific strategies for some steps in the scientific method.

Step 2: Perform Research

We require our advanced and older students to find research independently and provide them with only a few resources or guidelines. For example, Tara's AP Environmental Science students are required to find their research using at least one Internet site, two scholarly articles, an interview, and one library book.

English language learners can be shown a closed-captioned English video that provides information on the topic being researched. Many videos on YouTube have the option of closed-captioning. We allow them to watch videos as many times as they need. Or, students can watch videos or read articles in their home language on the same topic. See the Technology Connections section for more bilingual resources.

These resources can be provided to students prior to the lesson being taught in class. This strategy is a modification of the Preview-View-Review sequence often used in bilingual classes where the lesson is previewed in the home language, taught in English, and then reviewed in the home language (see Larry Ferlazzo's blog titled “The Best Resources Explaining Why We Need to Support the Home Language of ELLs,” details in Technology Connections).

Students with focus issues or high anxiety can be provided with a list of specific questions they need to answer while they perform their research. Students are then able to focus on the specific questions they've been assigned so they can accomplish more in the allotted time (Minahan, 2017, pp. 2–3). For example, if the experimental question was, “What is the most efficient process to clean birds after an oil spill?” students would be provided with the following list of research questions:

  1. What are the physical characteristics of oil?
  2. Why can't birds wash the oil out of their own feathers?
  3. How do people help birds who are covered in oil? How well do these processes work?
  4. How does oil negatively affect birds?

Table 3.3 Scientific Method Pretest Skills

Station number Scientific method skill being tested
1 Identifying independent and dependent variables
2 Identifying experimental controls
3 Making data tables
4 Writing a hypothesis using “If…then…because…” format
5 Making graphs

Step 3: Write a Hypothesis

When we teach the scientific method to younger students, we have all lab groups perform the same experiment with the same variables. We tell the students what their variables are and we work as a class to write the hypothesis. In order to prevent preconceived ideas of what the results should be, the teacher doesn't model the experiment first. However, the teacher needs to have previously provided various examples of other experiments on different topics.

Steps 6 and 7: Analysis and Conclusion

Some students' IEPs (Individualized Educational Plans) have an accommodation that requires teachers to minimize the amount of writing requirements. In that case, we don't require students to write both a Discussion of Results and a Conclusion. Instead, they write one document that covers both steps. We provide a structured lab report with sentence starters for these students, which is Figure 3.12: Discussion of Results and Conclusion Modified Version.

High School Students

If we assume all of our high school students have the same background knowledge about the scientific method, we may not be providing equitable instruction. Therefore, we give high school students a pretest, which consists of five lab stations. Each station tests a student's ability to use the various skills required by the scientific method. Table 3.3: Scientific Method Pretest Skills lists the scientific method skill for each of the five stations.

The stations are provided in Figure 3.13: Scientific Method Pretest Stations. We print each station on a separate sheet of paper and post them around our classroom. Students are allowed to move freely from station to station, in no particular order. To maximize on-task behavior, we have two of every station around our room. We've found that it typically requires approximately 45–60 minutes to complete all five stations.

Prior to beginning the pretest, we explain to students that this is a non-graded activity and their results will indicate what aspects of the scientific method we need to teach prior to performing experiments. We ask them, “Please help us become better teachers.” We emphasize that we need students to complete the tasks individually so that we can get a clear picture of individual student needs. We also monitor during the activity to ensure students are working independently. Students are provided with Figure 3.14: Scientific Method Pretest—Student Answer Sheet.

The answer key for each station is provided in Figure 3.15: Scientific Method Pretest—Answer Key.

As we grade the students' answer sheets, we note which students need more practice in the various scientific method concepts. The next several days are then used to provide more practice and instruction in the areas that students struggled with the most. For example, students who cannot accurately identify independent and dependent variables are placed in a small group and challenged to work together to complete Figure 3.2: Identifying Independent and Dependent Variables. Table 3.4 lists the scientific method skills and the coordinating activities that can be used to help students practice them. Students who perform all five stations correctly are asked to help their peers. They are instructed not to give the answers to their classmates but instead to explain the process they used to complete the tasks.

Students who need more practice making graphs are provided with Figure 3.9: Example and Checklist—Making Graphs. They create a graph using provided data like that found in Table 3.5: Data for Graph Practice.

Table 3.4 Scientific Method Skill and Coordinating Learning Activity

Scientific method skill Coordinating learning activity
Identifying independent and dependent variables Figure 3.2: Identifying independent and dependent variables
Identifying experimental controls Figure 3.7: Finding controls and making data tables
Making data tables Figure 3.7: Finding controls and making data tables
Writing a hypothesis using “If…then…because…” format Figure 3.4: How to write a hypothesis
Making graphs Figure 3.9: Example and checklist—making graphs

Table 3.5 Data for Graph Practice

Car color Internal temperature (°C) External temperature (°C)
Red 25.5 18.3
Blue 25 18.3
White 21.7 18.3
Black 27.8 18.3

Student Handouts and Examples

  • Figure 3.1: Student Research Organizer (Student Handout)
  • Figure 3.2: Identifying Independent and Dependent Variables (Student Handout)
  • Figure 3.3: Identifying Independent and Dependent Variables—Answer Key
  • Figure 3.4: How to Write a Hypothesis (Student Handout)
  • Figure 3.5: How to Write a Hypothesis—Answer Key
  • Figure 3.6: Student Materials List (Student Handout)
  • Figure 3.7: Finding Controls and Making Data Tables (Student Handout)
  • Figure 3.8: Finding Controls and Making Data Tables—Answer Key
  • Figure 3.9: Example and Checklist—Making Graphs (Student Handout)
  • Figure 3.10: Discussion of Results (Student Handout)
  • Figure 3.11: Conclusion (Student Handout)
  • Figure 3.12: Discussion of Results and Conclusion Modified Version (Student Handout)
  • Figure 3.13: Scientific Method Pretest Stations
  • Figure 3.14: Scientific Method Pretest—Student Answer Sheet (Student Handout)
  • Figure 3.15: Scientific Method Pretest—Answer Key

What Could Go Wrong?

The most common incident that causes student anxiety is when they don't get data that supports their hypothesis. When this happens, students believe they are going to fail the lab. We've learned through the years that the best way to combat this is to be proactive. As mentioned earlier, prior to performing any experiment, we explain to students that their grade is based on how they interpret their data and not on the data itself. We tell them that when scientists obtain data they are not expecting, it indicates that they learned something, which is the purpose of doing science!

We share examples of how scientists didn't obtain the data they were expecting, which led to major scientific advances, including the invention of the microwave, Super Glue, the Slinky, and pacemakers (Biddle, 2012). We make a point of highlighting people of color and women who have found success through failure. Here are a few of our favorites, some of which can be found in the Business Insider article “These 10 Inventions Were Made by Mistake” (Krueger, 2010).

  • American chef Ruth Wakefield ran out of baker's chocolate while making chocolate cookies. She attempted to solve the problem by adding small sweetened chocolate pieces to the cookie dough, hypothesizing that the chocolate would melt and make chocolate cookies. However, the small pieces stuck together and the first chocolate chip cookie was invented.
  • Chef George Crum, who had an African-American father and a Native-American mother, served a customer a side dish of potatoes. The customer sent the plate of potatoes back to the kitchen multiple times demanding the potatoes be cut thinner and fried again. Crum hypothesized that if he cut the potatoes thinner than he had ever cut potatoes and fried them until they had a very crunchy texture, then the customer would finally be satisfied. The customer loved his thin crunchy potatoes and Crum soon opened his own restaurant that included a basket of potato chips on every table.
  • American chemist, Patsy Sherman, accidentally invented Scotchgard with her partner, Sam Smith. She was experimenting on a rubber material that would not deteriorate when it was exposed to jet aircraft fuels. During the experiment, an assistant unintentionally dropped the rubber material and some of it landed on Sherman's white canvas tennis shoes. Her shoes' structure didn't change but it repelled water and oil. Three years later, Sherman and Smith developed the stain repellent, Scotchgard, all due to an error made during an experiment.

Of course, this is just a very tiny effort at being culturally responsive. We share many more substantial strategies in Chapter 14: Strategies for Cultural Responsiveness.

The most common incident that causes us anxiety is when one or two lab groups gets grossly behind in the experimental process. When we were new teachers, this was the most challenging part of labs. Over the years we've found that keeping the lab groups on the same schedule is logistically imperative because otherwise we are challenged with finding something for the rest of the class to do while the remaining lab groups complete their experiments.

To keep all groups on the same schedule, we provide enough time for students to complete every step of the scientific method in class. We find that the groups who fall behind are typically the ones who do not complete their homework. To address this issue, we don't assign homework and instead use class time to complete all necessary work, including the preparation, data collection, and conclusion. This process also allows us to provide support and ensure students are on task, which is something that can't be done when they take work home.

Another challenge relates to the scientific method itself. There are inherent problems with the scientific method; for example, it is impossible to always control every variable and to eliminate scientists' biases. When these situations arise in our classrooms, we use them to teach our students about the struggles of real scientists. We teach students that when an experiment isn't completed perfectly, it's acceptable, but they must describe the errors in their lab reports. There is an area for students to communicate their errors in Figure 3.10: Discussion of Results when they complete Step 5: Analyze Results.

Technology Connections

GENERAL SCIENTIFIC METHOD RESOURCES

There are many entertaining and educational videos on YouTube that walk students through the scientific method steps. Be careful, though, because many of them don't include Step 7: Publish Results. Larry Ferlazzo's Edublog includes a list of online videos that teach the scientific method. The list can be found at “The Best Videos for Learning About the Scientific Method” (http://larryferlazzo.edublogs.org/2017/03/10/the-best-videos-for-learning-about-the-scientific-method).

Teachers can search “scientific method” in any of these educational sites to find activities other teachers have already created:

Students can be assigned online activities to complete as a class (such as Quizlet Live) or individually (such as Quizlet Match). Additional ways to leverage these sites in a classroom can be found in Chapter 16: Strategies for Reviewing Content.

There are many online science resources available in multiple languages. See Larry Ferlazzo's blog at “The Best Multilingual and Bilingual Sites for Math, Social Studies, & Science,” which can be found at http://larryferlazzo.edublogs.org/2008/10/03/the-best-multilingual-bilingual-sites-for-math-social-studies-science.

We use Science Buddies (www.sciencebuddies.org) for experiment ideas and supporting documentation, such as a sample materials lists and step-by-step procedures.

RESEARCH RESOURCES

When we provide research for our students, we begin searching online by adding the phrase “for kids.” For example, if we were going to search for sites that teach students about osmosis, we would search for “osmosis for kids.” We've found that student-friendly results are more common using this trick.

When we want to provide our students with articles that are about current events or real-life applications of a concept, our favorite source is Newsela (https://newsela.com). This website has thousands of articles that are offered in five different lexile levels ranging from 690 L to more than 1,230 L. And, some of the articles are offered in both English and Spanish. For schools that don't provide students with online access, there is a printer-friendly version of each article so teachers can provide their students with a hard copy.

There are additional websites that offer articles. Larry Ferlazzo's Websites of the Day, “The Best Places to get the ‘Same’ Text Written for Different ‘Levels’” contains a list of great sources (http://larryferlazzo.edublogs.org/2014/11/16/the-best-places-to-get-the-same-text-written-for-different-levels).

When performing research, ELL students can be given the topic prior to the lesson being taught in class. This strategy is a modification of the Preview-View-Review sequence often used in bilingual classes where the lesson is previewed in the home language, taught in English, and then reviewed in the home language. See Larry Ferlazzo's blog titled “The Best Resources Explaining Why We Need to Support the Home Language of ELLs” for more online resources to support ELL students (http://larryferlazzo.edublogs.org/2017/04/10/the-best-resources-explaining-why-we-need-to-support-the-home-language-of-ells).

PUBLISH RESULTS RESOURCES

There are many organizations designed to assist teachers in connecting with other classes around the world. These “sister classes” can provide an “authentic audience” where students can share the results of their experiments. See “The Best Ways to Find Other Classes for Joint Online Projects” for more information (http://larryferlazzo.edublogs.org/2009/05/30/the-best-ways-to-find-other-classes-for-joint-online-projects).

Figures

Figure 3.1 Student Research Organizer (Student Handout)

Figure 3.2 Identifying Independent and Dependent Variables (Student Handout)

Figure 3.3 Identifying Independent and Dependent Variables—Answer Key

Figure 3.4 How to Write a Hypothesis (Student Handout)

Figure 3.5 How to Write a Hypothesis—Answer Key

Figure 3.6 Student Materials List (Student Handout)

Figure 3.7 Finding Controls and Making Data Tables (Student Handout)

Figure 3.8 Finding Controls and Making Data Tables—Answer Key

Figure 3.9 Example and Checklist—Making Graphs (Student Handout)

Figure 3.10 Discussion of Results (Student Handout)

Figure 3.11 Conclusion (Student Handout)

Figure 3.12 Discussion of Results and Conclusion Modified Version (Student Handout)

Figure 3.13 Scientific Method Pretest Stations

Figure 3.14 Scientific Method Pretest—Student Answer Sheet (Student Handout)

Figure 3.15 Scientific Method Pretest—Answer Key