Who makes the “best” paper towel? How could you find out? In this Explore activity, Putting Paper Towels to the Test, you will do an investigation using paper towels. By the end of the investigation, you will answer the question about who makes the best paper towel. You will test a few brands of paper towels during this investigation. Once you have learned how to test these brands, you can test other products on your own. Testing products is one step toward being a wise consumer. Materials
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Look back at your rankings from Step 4 and at your answer to Question 1 in the Reflect and Connect section of the Engage activity. As a team, choose one property from your list that you want to test. Hint
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As a team, come up with a definition for the property you chose. Relate your definition to paper towels. Hint
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In your technology notebook, list the variables you will need to control to make the test fair. Hint
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With your team, write a brief procedure of how you will perform the investigation. Your procedure should list each step that you will complete in the test. See figure 1-3 for an example of a way to set up the investigation. If you need additional materials, ask your teacher to supply them.
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Draw a picture to show how you are going to set up the investigation. Be sure to add labels to help someone else understand the parts in your picture.
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Draw a data table that you will use to record your results. The table should show what you are testing, what the results are, and how you rank the paper towels.
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Explain your answers to Steps 2–6 to your teacher. Once your teacher approves of your answers, you can move on to the next step.
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Obtain the materials to perform the test. Hint
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Conduct your investigation by testing each paper towel sample for the property your team chose. Be sure to record your results in your data table.
Caution: Be sure to clean up any spilled water immediately. -
Rank the paper towels from best to worst based on how each brand met your team’s definition of the property. Hint
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Share the results of your investigation by recording your rankings on the class data table.
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Participate in a class discussion about the investigations. Be prepared to share your team’s definition, how your team performed the test, and what your team found.
Activity Overview
In this Explore activity, Putting Paper Towels to the Test, students will design an investigation to test one of the properties that might be important to consumers buying paper towels. Students will choose a property, design a fair test, decide on the variables that need to be controlled, and carry out the test. There is a focus on sharing and effectively communicating results.
Before You Teach
Materials
For each class of 30 students, teams of 3:
- 1 balance
- 1–1.5 kg of washers, pennies, or other objects of uniform mass
- 10 trays to help contain water
- 10 rulers
- 10 large plastic beakers or measuring cups
- 1 roll each of at least 5 different brands of paper towels
- a source of water (sink or beakers/bottles containing water)
- other materials that might help students complete the investigation, such as rubber bands (optional)
- mop and bucket (optional)
- 8 copies of Master 1-1, The Process of Technology Design, cut into fourths
- tape or glue
- pens or pencils of different colors
Advance Preparation
The Advance Preparation section of the Engage activity suggests that you buy the paper towels you need for this activity at the same time you purchase the paper towels for the Engage activity. If you have not done so already, purchase at least 5 brands of paper towels. It is suggested that you have 1 roll per class section that you are teaching. Try to choose at least 3 of the brands listed in figure 1-4 of the student edition.
If you do not have a water source, such as a sink, in your classroom, you may wish to prepare beakers or bottles containing water for students to use during the investigation.
In Reflect and Connect Question 3, students determine what stage they were doing on The Process of Technology Design graphic. This graphic is on Master 1-1, The Process of Technology Design. Before class, you should make copies of this master and cut each copy into fourths. Students will put the graphic into their technology notebooks at the time they are asked in the Reflect and Connect question.
You may wish to preview Chapter 3, “Testing Your Way to a Solution,” for its discussion on fair tests and variables. Although students will need some limited knowledge about these ideas for their investigation in this activity, that will be a focus in a later chapter. Decide how much information your students need to know at this point to complete their investigation.
As You Teach
Outcomes and Indicators of Success
By the end of this activity, students will
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become interested in determining the “best” brand in a group of similar products.
They will show their interest by
- developing tests to determine the best paper towel for a given property
- ranking brands of paper towels from best to worst for that particular property.
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design and carry out a scientific test.
They will show their ability by
- creating and using a definition for the property they are measuring
- controlling variables in the investigation that they devise to determine the ranking of the paper towels
- creating a data table in which they record the results of the tests.
Strategies
Getting Started
Begin by having students refer back to the chapter organizer. Remind them that they saw some paper towels in the Engage activity and thought about which brand they would buy. They did this without touching or using the paper towels. Then, have them read the introduction to the activity.
Cautions
Students will work with water in this activity. Pay attention to make sure that spilled water does not remain on the floor, as it could be slippery and dangerous. Have students wipe up spills immediately and watch where they step. You may wish to have a bucket and mop available, particularly if you are using beakers or bottles of water as the water source.
Also caution students against throwing objects at the paper towels that someone is holding during a strength test. Throwing objects could injure students.
Process and Procedure
Students should continue to work in their teams of three from the Engage activity. In Step 1, they refer to their brainstorming lists and comparisons to their teammates’ lists from the Engage activity. They should use this information to select a property to test. Be sure they read the hint behind the link so that they realize they need to test something that is measureable. For example, they cannot just look up the cost for each brand, which is not testable. Similarly, they cannot just look on the package to find the longest roll. They should choose a property such as absorbance, strength, wet strength, or scrubbing ability. Use your discretion if they ask to use additional materials.
Have students come up with a definition of the property. If your students are familiar with the term “operational definition,” you may want to use that term. Students should define the property as it relates to paper towels. The hint behind the link may help them get started. For example, a strong paper towel can hold more weight than a weak paper towel, even if the towel is wet. Encourage students to develop a definition that will allow them to test the property without wasting too many paper towels. For example, they might want to test absorbency by putting a fixed amount of water on layers of paper towels, then seeing how many layers the water soaks through. For that test, using layers of paper towels cut into fourths would work as well as layers of full paper towels and would save many towels.
Students should make a list of the variables that they will need to control in the test. If they are not familiar with experimental design, you may need to spend some time talking about variables and what needs to be controlled. Realize, however, that Chapter 3, "Testing Your Way to a Solution," focuses on variables and designing a fair test, so you should not spend too much time on this idea. Make sure students read the hint.
Have students write out the procedure for the investigation. They should not complete the test at this point. Base your expectations for the detail in the procedure on their experience with writing procedures. If they have a lot of experience, you can expect more detailed procedures than if this is the first time they have written out the steps of an investigation.
Students should draw a picture of the setup. Remind them to use labels so that other people can understand their diagrams.
Have students draw a data table in preparation for the investigation. It is suggested that they include three items, but they should realize that they will likely need more descriptive headings than simply the items listed in the step.
Students should get your approval before beginning the investigation. You should check the property they are testing, the variables, and whether the procedure makes sense. You may also want to see if they have considered any safety concerns in the investigation. This is an opportunity to assess students’ understanding of experimental design; however, it is important to base your expectations on students’ experience with this skill.
Students should send one team member to retrieve all the materials. This will cut down on the number of students gathering around the materials.
Give students plenty of time to complete the investigation. You will likely need to remind them to record their results.
Emphasize that students should use evidence from the investigation to rank the paper towels. The hint provides a brief definition of evidence. You may need to spend additional time on the meaning of evidence, depending on your students’ experience.
Create a class data table on which students can record their results. If you have an interactive whiteboard, this is a good opportunity to use it to create the data table. Along the left side, list the different brands of paper towels that students tested. Across the top, leave spaces for students to write the property they were testing. They should then fill in their rankings. If more than one team tests a particular property, the rankings should be listed in separate columns. Figure T1-1 shows an example of a class data table. Keep the table so that students can refer back at it in Step 1 of the Explain activity.
Lead a class discussion about the results. You may wish to have students discuss the property the team tested, its definition, how it tested the property, and what its results are. Help students think about whether the brands ranked the same overall. If more than one group tested the same property, you might discuss whether the brands ranked the same with the different teams’ tests. If the brands did not rank the same for a given property, have students think about why that may have happened. Also, have students think about whether the different definitions for a given property were similar or different.