papertowel

TheQuicker Picker Upper!

Paper Towel Testing
(Adapted & Written byDavid T. Crowther)

Introduction:

There are many ways to explore the naturalworld ranging from general observations to investigations to tightly controlledexperiments. The purpose of the elementary science experience is to helpchildren to better understand the world around them by utilizing scienceprocess skills in investigations and to begin to learn the body of knowledgethat science has accumulated. Children need experience in learning thebasic steps of investigation in order to begin to understand how scienceworks. Many of us grew up knowing this investigative and experimental procedureas "The Scientific Method." However, scientists, science educators, teachers,and curriculum writers today know that there is more than ONE way to investigateor experiment with different phenomenon. The purpose of this lesson isto show one way to use an organized approach to investigation in orderto compare and contrast different paper towel brands for their absorptioncapabilities. Additionally, this concept under investigation can be appliedto the scientific body of knowledge demonstrating how plants take waterin through their roots through the stems and on out to the leaves in aprocess called cohesion-tension. This is also the same process used inmany different practical applications found in the household includingevaporative coolers, humidifier filters, spills on carpet, and water soakeddrywall (to just name a few).

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

Formal experiments are highly controlledinvestigations where the results of the specific relationship between themanipulated (independent) and responding ( dependent) variables studiedare able to be used to predict how one would see the same phenomena innew situation For example the strength of a type of concrete based on varyingthe amount of mortar used in the mix. The paper towel situation is descriptiveresearch because it describes what one would expect or predict to happenfor only the specific brand of paper towels which were studied. It is adescriptive type of investigation (as compared to a true experiment) sinceit is impossible to control all the conditions in the comparison beinginvestigated. With this type of scientific investigation the predictionis 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 abouthow "Bounty" would work but clearly does provide a base to predict howrapidly any sample of Brawny would work. (EJSE reviewer).

Please note: Paper towel testing isa 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 modelwas to write the paper towel lab which had the National Science EducationStandards referenced, both process and a content, and was written in the5 E learning cycle format. Additionally, it has provided a nice forum onthe distinctions between scientific experiments and investigations.

TheQuicker Picker Upper!

Paper Towel Testing
(Adapted & written byDavid T. Crowther)

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

Proficiencies: (National Science EducationStandards)(NRC, 1996)
Content:

1. Students will understand the conceptof "wicking" cohesion-tension as applied to absorption in a paper toweland the process through the xylem in a plant.

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

2. Students will develop conclusionsbased upon Investigation.

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

3.Students will know and utilize themajor steps in scientific investigations.

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

Process:

1. Students will use various scienceprocess 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 recycledpaper towel brand)
(Each group of 2 - 4 people willneed a set of the following)
A set of plastic beakers (50 ml to 1000ml).
A set of plastic graduated cylinders (10ml to 100 ml).
A set of syringes: 1 each of 60 ml plasticsyringe. 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 shouldhave a working knowledge of the "wicking"process that is used in plantsto 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 reachthe top of the tallest trees. Many experiments have shown that water fromroots rises through root xylem to stem xylem to the xylem in the veinsof leaves. This movement is against the force of gravity. Imagine thatyou 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 howhard you try you cannot suck the root beer up from the bottle, not evenwith a vacuum pump.

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

Therefore, water moves through plants in asimilar way that water moves in a paper towel. If you put the dry papertowel into water, the water will travel up the paper towel utilizing thecohesion-tension part of the plant process. The paper towel fibers providethe 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 transpirationis not taking place creating a constant source of negative pressure andtherefore the "wicking" process will quit when it reaches and equilibriumassociated with the column of water, pressure and gravity associated inthe paper towel.
This is also the same process used inmany different practical applications found in the household includingevaporative coolers, humidifier filters, spills on carpet, and water soakeddrywall (to just name a few).

The teacher should have a working knowledgeof 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 willbe a prediction)
Design and carry out an investigation controllingfor 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 shouldhave some background knowledge on how to set up and design an investigation.If no prior knowledge exists, this investigation can then be used to introducean investigatory process. Students should also be introduced to the fact that they need to controlvariables in order to answer questions of interest and base their answersto questions on the evidence they can observe and collect as part of theinvestigation. This lab can be done as an introduction to xylem and phloemin a plant and/or the process of transpiration and cohesion-tension ina plant.

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

Engagement:

Scenario: It is late at night and youhave just finished writing your 20 page report for class. As you reachover 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!! Smokebegins 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 brandsof paper towels. Which paper towel will you choose for this emergency!!

Exploration:

Using the scientific investigation processbelow (or one of your own), design and carry out an investigation thatwill determine which paper towel is the best for the job. You will be workingin 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 ofscience including classifying, communicating, connecting, hypothesizing,inferring, interpreting data, measuring, modeling, observing, patterning,problem solving, predicting, questioning, reasoning, researching.

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

Problem: Which paper Towel absorbsthe best? (Perhaps you have a different or better question that you wouldlike to use.)
Hypothesis / Prediction: Which brandof paper towel do you think will work the best for your experiment??
Prior Knowledge / Research: What doyou 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 foras many variables as possible: Hint: Are the paper towels the samesize? 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 yourdata
Prepare a short discussion about your investigationandits design to share with the rest of the class.

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

Elaboration:
Each group will then receive a carnationand 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 throughthe paper towel experience. Be sure to then have the students "discover"through questioning how cohesion-tension in plants works.

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

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

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

Clean - up:Each group will cleanup their projects and return the measuring devices to the central supplylocation. Extra effort will be applied to cleaning up any water spillsfor safety reasons.

References:

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

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

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

Note: Paper towel testing is a verypopular lab. It is in many activity books and therefore is not, by anymeans, a creation of this author. The purpose of this activity model wasto write the paper towel lab which had the National Science Education Standardsreferenced, both process and a content, and was written in the 5 E learningcycle format.

TheQuicker Picker Upper!

Paper Towel Testing
(Adapted & written byDavid T. Crowther)

Student Activity Sheet

Scenario:

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

Using the investigation procedure below,(or another procedure you are aware of ) design and carry out an investigationthat determines which paper towel is the "Quicker Picker Upper." Concentrateon using the following skills during your investigation: communicationbetween 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), DataCollector and Recorder (DCR), Experimental Specialist (ES), and a ProjectReporter / Time Keeper (PR/TK).

Materials List:

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

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

Problem: Which paperTowel absorbs the best? (Perhaps you have a different or better questionthat 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 aboutpaper towels? Which paper towel is known to be the "Quicker Picker Upper?"http://www.pg.com/about/products/products.htm
Design your investigationcontrolling for as many variables as possible) Hint: Are thepaper towels the same size? Can you quantify your results?
Conduct your investigationat least three (3) different times
Collect data for each trialinvestigation (3) different times
Make a graphic representationof your data (Bar graph is fine)
Formulate a conclusion basedupon your data
List implications that address how the investigation conclusionsapply to other situations.
Prepare a short discussionabout your investigation/implications and its design to share with the rest of the class.

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