papertowel

The Quicker Picker Upper!

Paper Towel Testing
(Adapted & Written by David T. Crowther)

Introduction:

There are many ways to explore the natural world ranging from general observations to investigations to tightly controlled experiments. The purpose of the elementary science experience is to help children to better understand the world around them by utilizing science process skills in investigations and to begin to learn the body of knowledge that science has accumulated. Children need experience in learning the basic steps of investigation in order to begin to understand how science works. Many of us grew up knowing this investigative and experimental procedure as "The Scientific Method." However, scientists, science educators, teachers, and curriculum writers today know that there is more than ONE way to investigate or experiment with different phenomenon. The purpose of this lesson is to show one way to use an organized approach to investigation in order to compare and contrast different paper towel brands for their absorption capabilities. Additionally, this concept under investigation can be applied to the scientific body of knowledge demonstrating how plants take water in through their roots through the stems and on out to the leaves in a process called cohesion-tension. This is also the same process used in many different practical applications found in the household including evaporative coolers, humidifier filters, spills on carpet, and water soaked drywall (to just name a few).

Finally, this lesson will use investigation procedures rather than formal experimentation procedures due to the nature of the investigation. One of the EJSE reviewers precisely stated the difference between experimentation and less formal investigations.

Formal experiments are highly controlled investigations where the results of the specific relationship between the manipulated (independent) and responding ( dependent) variables studied are able to be used to predict how one would see the same phenomena in new situation For example the strength of a type of concrete based on varying the amount of mortar used in the mix. The paper towel situation is descriptive research because it describes what one would expect or predict to happen for only the specific brand of paper towels which were studied. It is a descriptive type of investigation (as compared to a true experiment) since it is impossible to control all the conditions in the comparison being investigated. With this type of scientific investigation the prediction is what is critical. As the word hypothesis is used it means making a prediction. To learn about "Brawny" doesn't tell one a reliable and valid thing about how "Bounty" would work but clearly does provide a base to predict how rapidly any sample of Brawny would work. (EJSE reviewer).

Please note: Paper towel testing is a very popular lab. It is in many activity books and therefore is not, by any means, a creation of this author. The purpose of this activity model was to write the paper towel lab which had the National Science Education Standards referenced, both process and a content, and was written in the 5 E learning cycle format. Additionally, it has provided a nice forum on the distinctions between scientific experiments and investigations.

The Quicker Picker Upper!

Paper Towel Testing
(Adapted & written by David T. Crowther)

Grade Level: 5 - 8
Objective:
By the end of the lesson the students will be able to determine which paper towel absorbs liquid the fastest through utilizing scientific investigation and science process skills.

Proficiencies: (National Science Education Standards)(NRC, 1996)
Content:

1. Students will understand the concept of "wicking" cohesion-tension as applied to absorption in a paper towel and the process through the xylem in a plant.

NSES - Content Standard 5-8, Life Science, Content Standard C: Structure and function in living
organisms & Diversity and adaptations of organisms.

2. Students will develop conclusions based upon Investigation.

NSES - Content Standard 5-8, Science as inquiry, Content Standard A: Abilities necessary to do
scientific inquiry.

3.Students will know and utilize the major steps in scientific investigations.

NSES - Science Content Standard 5-8, Science as inquiry, Content Standard A: Abilities
necessary to do scientific inquiry.

Process:

1. Students will use various science process skills including: classifying, communicating, connecting, hypothesizing, inferring, interpreting data, measuring, modeling, observing, patterning, problem solving, predicting, questioning, reasoning, researching, etc.

?(NSES - Science Content Standard 5-8, History and nature of science, Content Standard G:
Nature of science.

Materials List:

5 different brands of paper towels (Bounty, Brawny, store brand, generic brand, and Green Forest / or other recycled paper towel brand)
(Each group of 2 - 4 people will need a set of the following)
A set of plastic beakers (50 ml to 1000 ml).
A set of plastic graduated cylinders (10 ml to 100 ml).
A set of syringes: 1 each of 60 ml plastic syringe. 10 ml plastic syringe, 2 ml plastic syringe (without needles)
Food coloring (1 color per group)
Rulers (metric preferred)
Scissors
Stop watch
Graph paper
water source

Materials for Elaboration
1 Carnation for each group
2 tall 12 ounce cups per group
Food coloring (Blue, Green & Red)

Background Knowledge:

(Teacher) The teacher should have a working knowledge of the "wicking"process that is used in plants to absorb water from roots to the leaves and structures of the plant. Specifically, the "wicking" process is defined in plant physiology as Cohesion-tension.

Water must travel more than 100 m to reach the top of the tallest trees. Many experiments have shown that water from roots rises through root xylem to stem xylem to the xylem in the veins of leaves. This movement is against the force of gravity. Imagine that you are standing with along straw on top of a building three stories tall. The straw reaches into a bottle of root beer on the ground. No matter how hard you try you cannot suck the root beer up from the bottle, not even with a vacuum pump.

Water is thought to move by a process known as cohesion-tension. Under certain conditions, water can be pulled up a narrow tube if the water is in a continuous column. One condition is that the tube must have a very small diameter. (In small plants, the diameter is smaller than a human hair, but can be larger in larger plants as well.) A second condition is that the tube must be made of a material to which water molecules will adhere. These two conditions exist within the xylem cells of plants. Water molecules exhibit cohesion - they are attracted to adjoining water molecules, thus forming an unbroken chain of water molecules in each xylem tube. Tension is negative pressure that results from the pulling action of water molecules as they move out of the leaves during transpiration. The pull is transmitted through the column, and water is pulled from the roots up the plant to the leaves. Transpiration is the driving force of water transport, creating negative pressure that keeps water moving from the soil into the roots and up through the stems into each leaf. (BSCS, 1992, p. 496-497)

Therefore, water moves through plants in a similar way that water moves in a paper towel. If you put the dry paper towel into water, the water will travel up the paper towel utilizing the cohesion-tension part of the plant process. The paper towel fibers provide the small places for the columns of water to exist and for which to adhere. The result is the "wicking" process which is observable in the paper towel. It must be noted that the process in a paper towel differs because transpiration is not taking place creating a constant source of negative pressure and therefore the "wicking" process will quit when it reaches and equilibrium associated with the column of water, pressure and gravity associated in the paper towel.
This is also the same process used in many different practical applications found in the household including evaporative coolers, humidifier filters, spills on carpet, and water soaked drywall (to just name a few).

The teacher should have a working knowledge of the steps of general scientific investigations procedures which include: Determine a problem to study
Define the investigation question
Do background research / literature review - what is known about this problem?
Make a hypothesis (which in this case will be a prediction)
Design and carry out an investigation controlling for as variables as possible.
Compile data and note observations
Analyze data
Form a conclusion based upon the data analysis
Communicate the results

(Students) The students should have some background knowledge on how to set up and design an investigation. If no prior knowledge exists, this investigation can then be used to introduce an investigatory process. Students should also be introduced to the fact that they need to control variables in order to answer questions of interest and base their answers to questions on the evidence they can observe and collect as part of the investigation. This lab can be done as an introduction to xylem and phloem in a plant and/or the process of transpiration and cohesion-tension in a plant.

Safety: The only safety precautions for this lesson would include cautions on spilled water and slippery floors.

Engagement:

Scenario: It is late at night and you have just finished writing your 20 page report for class. As you reach over to turn on the printer for your computer you knock over the 72 oz. beverage that you have been drinking in order to keep you awake!! Smoke begins to pour out of your computer and the screen starts to go fuzzy. You run to the cupboard and discover that there are 5 different brands of paper towels. Which paper towel will you choose for this emergency!!

Exploration:

Using the scientific investigation process below (or one of your own), design and carry out an investigation that will determine which paper towel is the best for the job. You will be working in cooperative groups of four. Cooperative assignments are: Materials Manager (MM), Data Collector and Recorder (DCR), Experimental Specialist (ES), and a Project Reporter / Time Keeper (PR/TK).

Encourage the use of process skills of science including classifying, communicating, connecting, hypothesizing, inferring, interpreting data, measuring, modeling, observing, patterning, problem solving, predicting, questioning, reasoning, researching.

Allow the students to use the scientific investigation procedure below (or if they have alternative ideas on how to gather information allow that) to design and carry out an investigation that determines which paper towel is the "Quicker Picker Upper"

Problem: Which paper Towel absorbs the best? (Perhaps you have a different or better question that you would like to use.)
Hypothesis / Prediction: Which brand of paper towel do you think will work the best for your experiment??
Prior Knowledge / Research: What do you know about paper towels? What can you find on the WWW about paper towels? Which paper towel is known to be the "Quicker Picker Upper?" http://www.pg.com/about/products/products.htm
Design your investigation controlling for as many variables as possible: Hint: Are the paper towels the same size? Can you quantify your results?
Conduct your investigation at least three (3) different times
Collect data for each trial investigation (3) different times
Make a graphic representation of your data (Bar graph is fine)
Formulate a conclusion based upon your data
Prepare a short discussion about your investigation and its design to share with the rest of the class.

Explanation:
The explanation phase of this lesson includes each group sharing their investigational process and results from their individual group investigations. The teacher / facilitator should point out the different processes that each group used to investigate their problem. Also, the teacher / facilitator should lead a discussion in comparing and contrasting the different results of each of the groups. The explanation of cohesion tension could then be facilitated through how this process is identified in a plant.

Elaboration:
Each group will then receive a carnation and put it in a cup of colored water and observe it for 24 - 48 hours. Through research, have students compare and contrast what was learned through the paper towel experience. Be sure to then have the students "discover" through questioning how cohesion-tension in plants works.

Evaluation:
(Formative) Formative evaluation of this lesson will be conducted through teacher observation and questioning. Completion of the project with a relatively solid understanding of the scientific process and results will add to the evaluation.

(Summative) Summative evaluation will include a copy of the design of the investigation and results from each trial. Additional evaluation will come from a journal entry comparing and contrasting paper towel testing with cohesion-tension in a plants xylem.

Closure:
Close the lesson by restating that the students learned how to conduct an investigation and the challenges (procedure, variables, data, etc.) associated with setting up that process. Additional knowledge gained from this investigation lead to new knowledge about how plants carry water through their stems, branches and leaves by cohesion tension through the xylem.

Clean - up:Each group will clean up their projects and return the measuring devices to the central supply location. Extra effort will be applied to cleaning up any water spills for safety reasons.

References:

BSCS (1992). Biological science, An ecological approach. Seventh edition. Dubuque, IA. Kendall Hunt.

Lawrence Hall of Science (1987). Paper Towel Testing. Great Explorations in Math and Science (GEMS). Berkeley, CA. University of California.

National Research Council. (1996). National Science Education Standards. Washington D.C. National Academy Press

Note: Paper towel testing is a very popular lab. It is in many activity books and therefore is not, by any means, a creation of this author. The purpose of this activity model was to write the paper towel lab which had the National Science Education Standards referenced, both process and a content, and was written in the 5 E learning cycle format.

The Quicker Picker Upper!

Paper Towel Testing
(Adapted & written by David T. Crowther)

Student Activity Sheet

Scenario:

It is late at night and you have just finished writing your 20 page report for class. As you reach over to turn on the printer for your computer you knock over the 72 oz. beverage that you have been drinking in order to keep you awake!! Smoke begins to pour out of your computer and the screen starts to go fuzzy. You run to the cupboard and discover that there are 5 different brands of paper towels. Which paper towel will you choose for this emergency!!

Using the investigation procedure below, (or another procedure you are aware of ) design and carry out an investigation that determines which paper towel is the "Quicker Picker Upper." Concentrate on using the following skills during your investigation: communication between group members, hypothesizing, inferring, interpreting data, measuring, observing, patterning, problem solving, predicting, questioning, reasoning.
You will be working in cooperative groups of four. Cooperative assignments are: Materials Manager (MM), Data Collector and Recorder (DCR), Experimental Specialist (ES), and a Project Reporter / Time Keeper (PR/TK).

Materials List:

5 different brands of paper towels (Bounty, Brawny, store brand, generic brand, and Green Forest / or other recycled paper towel brand)

(Each group of 2 - 4 people will need a set of the following)
A set of plastic beakers (50 ml to 1000 ml).
A set of plastic graduated cylinders (10 ml to 100 ml).
A set of syringes: 1 each of 60 ml plastic syringe. 10 ml plastic syringe, 2 ml plastic syringe (without needles)
Food coloring (1 color per group)
Rulers (metric preferred)
Scissors, Stop watch, Graph paper, water source

Problem: Which paper Towel absorbs the best? (Perhaps you have a different or better question that you would like to use.)
Hypothesis / Prediction: Which brand of paper towel do you think will work the best for your experiment??
Prior Knowledge / Research: What do you know about paper towels? What can you find on the WWW about paper towels? Which paper towel is known to be the "Quicker Picker Upper?" http://www.pg.com/about/products/products.htm
Design your investigation controlling for as many variables as possible) Hint: Are the paper towels the same size? Can you quantify your results?
Conduct your investigation at least three (3) different times
Collect data for each trial investigation (3) different times
Make a graphic representation of your data (Bar graph is fine)
Formulate a conclusion based upon your data
List implications that address how the investigation conclusions apply to other situations.
Prepare a short discussion about your investigation/implications and its design to share with the rest of the class.

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