The best mopper upper

The best mopper upper

Pencil and paper
Overview
Using this Resource
Connecting to the Curriculum
Marking Student Responses
Working with Students
Further Resources
This task is about designing and carrying out a fair test.
Part 1       Observations / preparation This part of the task is about using observations to make a prediction. Obtain four (4) different paper towels and look at them carefully.

a)
Fill in the first three columns of the table below.
 
Table 1:  Data collected for four (4) different paper towels
  1 2 3 4 5
  Name of paper towel Describe the texture of the paper towel Describe or draw the pattern you can see Amount of water left in the container Amount of water absorbed by the paper towel
1

 

        
2

 

        
3

 

        
4

 

        

Now that you have looked at the pattern of fibres, you can answer the following questions.
b) i)
Prediction: Which paper towel do you think would absorb the most water?
 
 
 
  ii)
Explain why you chose that paper towel.
 
 
 
 
 
 
 
 
 
 
Part 2       Planning a fair test
This part of the task is about planning a fair test.
 
c)
Number the steps 1 – 6 (in the last column) to show the correct order that can be used to carry out a fair test on the best mopper upper paper towel.
The first step is identified for you.
STEPS ORDER
Measure how much water is left in the ice-cream container and record it in the chart.  
Pour 100 mL of water into the ice-cream container.  
Leave the paper towel to drip for a while.  
Test each paper towel individually by starting over again. 1
Work out how much water the towel soaked up and record it in the chart.  
Try to mop up the water in the ice-cream container with one paper towel.  
 
d)
 
What are you measuring in this investigation?
 
 
 
e)
What are you changing that will affect your measurements?
 
 
 
Use the steps above in the order that you identified to carry out the investigation. Record your data in columns 4 and 5 of the table in Part 1.
You used the steps to carry out a fair test but it was not fair. A part of the instruction for one of the steps was left out as well as a complete step.
 
f)
What part of an instruction or step was left out, making this investigation not a fair test?
 
 
 
 
 
 
Part 3       Reporting the results
This part of the task is about communicating your results.
 
g)
Circle the type of graph you will use to show the data recorded in column 5.
 
 
h)
Why did you choose this graph?
 
 
 
 
 
i)
What does a graph show that information in a chart does not?
 
 
 
 
 
 
 

Show the teacher which graph you will use before you graph the data.
 
j)
Use the information in the column 5 of the table to draw your graph in the box that follows. The title has been provided for you.
 
 
Amount of Water Absorbed by Different Paper Towels
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Part 4       Using the results
This part of the task is about interpreting the results.
k)
Use the graph to rank the paper towels in order from the best to the worst at mopping up spills.
 
 
BEST
 
WORST
 
l)
i) Was your prediction correct?    YES  /  NO  (circle one)

Return to Table 1 in Part 1. Look closely at the pattern you described in column 3 and the amount of water absorbed by each paper towel in column 5.

 
 
ii) What do you notice about the patterns you described in column 3 (the table in Part 1), how much water the paper towels absorb and your prediction?
 
 
 
 
 
 
 
 
 
m)
Why might people want to know about the absorbency properties of paper towels?
 

 
 
 
 
 
 
 
Task administration: 
This task can be completed with pencil and paper with other equipment.
 
Equipment:
Four different makes of paper towel, e.g., Softex, Tuffy, Handee, and Pams; measuring cup; 2 litre ice-cream container; scissors; water; ruler
  • The task could be a small group activity for its entirety or a combination of group and individual for the different parts.
  • The task can be broken into 4 sub-tasks – based around each part and carried out as separate tasks or as a combination of two tasks, e.g., Parts 1 and 2 and then Parts 3 and 4.
  • Part 2 – Students should be allowed to identify their sequence and then carry out the investigation. After carrying out the investigation this is an important place to stop and allow the class to discuss the sequence as well as fair test procedure. They are asked to identify a deliberate omission from the fair test procedure – using same size of paper towel or note that some instructions require further information e.g. 'drip time must be the same' or 'way to mop up in the container'. Allow students to repeat the test by incorporating them into their procedure. Stopping here provides discussion points (developing procedural knowledge) around aspects of fair testing by allowing students to clarify their own ideas about investigating in science.
  • Part 3 - Students are asked to choose an appropriate graph to represent the collected data (most appropriate is the bar graph – links to level 3 Statistics). Make sure that students show their graph before moving on to Part 4. This provides information about students' understanding of communicating in science.
  • Part 4 - Students will need to make connections between absorbency of a paper towel and texture/arrangement of fibres. Discussion of what students 'take away from the activities' is important as it links to participating and contributing in science.
  • There is a strong possibility that different brands may be made by the same manufacturer, and are therefore the same product.
Level:
3
Curriculum info: 
Science, Investigating in science, Material World
Key Competencies: 
Participating and contributing, Using language, symbols, and texts
Keywords: 
properties, physical properties, paper, investigation, fair testing, interpretation, evaluation, sequencing, planning investigations
Description of task: 
Task: Look at the arrangement of fibres for four different paper towels, arrange an appropriate sequence of instructions, carry out the instructions and then communicate the data in an appropriate graph that will help answer the question. Different elements of the nature of science are embedded throughout the tasks. Assessment focus: planning and carrying out a fair test, using evidence to answer a question.
Curriculum Links: 
Science capabilities
The capabilities focus is brought about by the conversations you have and the questions you ask.
 
Capability: Gather and interpret data
This resource provides opportunities to discuss methodology and questions you need to ask to check whether data is reliable in fair testing.
 
Science capabilities: 
Gather and interpret data
Making Better Sense: 
Physical Change
Answers/responses: 
a) First 3 columns of the chart completed accurately
1-2 gaps in the chart. Answer will depend on the paper towels investigated.
b) i)
ii)		 Names a specific paper towel.
The paper towel identified in i) has the fibres arranged so that there are larger 'spaces' (pores) between the fibres, thick or multi-weave and so there will be more space for the water to 'fill up'.
c)  

Correct sequence in the steps:

  1. Test each paper towel individually by starting over again.
  2. Pour 100 ml of water into the ice-cream container.
  3. Try to mop up the water in the ice-cream container with one paper towel.
  4. Leave the paper towel to drip for a while.
  5. Measure how much water is left in the ice-cream container and record it in the chart.
  6. Work out how much water the towel soaked up and record it in the chart.
d)  

Amount of water absorbed by the paper towel.
NOTE: Do not accept just absorbency as an answer. Students need to specify 'amount'.
e)   Changing the 'type' of paper towel
f)  

The size of the paper towels must be the same or it will not be a fair test.
NOTE: Students may want to discuss that one needs to 'mop up the water' for the same length of time or 'let it drip' for the same length of time. Although correct, the main variable that will affect the results a lot is the 'same size of paper towel'. Although students might mention correctly 'multiple/repeat tests' is missing, the table does not indicate that multiple/repeat tests are required to make it fair. This is a good discussion point for the class.
g)   The bar graph.
h)   Because what is being changed are specific objects/aspects (called discrete data) rather than continuous data one uses a bar graph.
i)   Graphs allow one to see the pattern (s) in the data more clearly than in a table/chart.
j)  

Correct graph:
- bar graph
- different paper towels on x-axis and labelled as Pam's, Huffy, etc.
- amount of water taken up on y-axis with regular intervals starting at '0'. Does not need to go to 100 ml.
- relates to the data recorded in the chart [ensure that column 5 data is used]
[Do not accept: 4 pie graphs or a line graph]
k)   Paper towels ranked accurately according to data from their graph.
l) i)
ii)

Answer matches their prediction and their results.
The more space (pores), bumpy texture and loose arrangement of the fibres, the more water the paper towel can hold.
m)   When mopping up spills in the house, one can use fewer paper towels (and therefore less waste) if the best mopper upper paper towel is used.

Based on a trial sample of 18 Y6 students November 2007.

Teaching and learning: 
Why is evaluating the instructions of a fair test an important skill for students to know?
The ability to evaluate aspects of an investigation that make it fair helps students question the validity of the data/evidence collected. It is important for students to question how the data/evidence is collected and its link to the purpose of the investigation. When different media communicate the results of scientific investigations to the public, a science literate person should be able to ask appropriate questions about the results, how it was collected, and whether the data answers the question, ie., it is valid.

 

Why is understanding properties of materials an important concept for students to know?
In this technological world, specific properties of the materials are used in the development of products, systems or environments. Understanding that all materials have specific properties and are used for a particular purpose does allow an individual to make wise choices in their selection of technological products that allow for sustainable use.

Key competencies
Key competencies that could be strengthened through this activity are:

Participating & contributing
Students are actively involved in a classroom discussion when they present their ideas about the omission of a step in the instructions. Individual contributions are valued by all and the class discussion results in a shared meaning of a fair test and demonstrates a respect for evidence. It also provides a science-like community for conversations to occur.

Using language, symbols and texts
Students will be making meaning of graphical representations using mathematical and science conventions when communicating results of their science investigation. Further practice with interpreting graphs and tables is also a part of developing literacy skills in science.

Fair Tests
Getting students to complete Parts 1 and 2 provides the teacher with important information about the development of procedural knowledge linked to plan and carry out investigations. The ability to follow a set of instructions is important as is the need to evaluate/critique the instructions during and after completing the investigation. Students should begin to develop the art of questioning whether the set of instructions (the design) will provide valid evidence that answers the question(s). This is just one part of understanding about investigating in science but an integral part.

A class discussion of students' evaluating the instructions (end of Part 2) will provide an opportunity for students to participate and contribute about what is not fair in the set of instructions. Working in small groups (3-4) first will allow students to listen and reflect on what others are saying in a safe environment. It also ensures that most if not all have opportunities to say what is not fair in the instructions. The sharing of small group responses provides more opportunities for students to engage in critical classroom discussions about key elements of a fair test. A discussion of whether multiple/repeat tests is critical to this investigation could arise. In this case the fact that everyone in the class is carrying out the same steps, with the same accuracy, does represent multiple tests. The small group/classroom discussion and debate allow the teacher to identify students' understanding.

Diagnostic and formative information: 

The following provides the teacher with some possible coaching questions to specific student responses. If student responses focussed on keeping the dripping time of the paper towel the same then ask a coaching question such as:

  • "What aspect other than type of paper towel will affect how long one will wait for the water to stop dripping?" A discussion and investigation of paper towel size would be appropriate direction to pursue. Should their responses focus on keeping the size of the paper towel the same then a coaching question such as
  • "What aspect other than using the same size for the different paper towels will affect how much water can be found in the paper towel?" The discussion and investigation could be carried out on the differing times the paper towels are allowed to drip.
  • The important question for students to keep asking themselves is: Will using these instructions collect valid evidence to answer the question?" Discussing the answer to this question helps students recognise key elements of a fair test.

Communicating in science is linked to a key competency – Using language, symbols and texts. It is important that students check with their teacher after selecting the appropriate graph (Part 3) and before drawing the graph. Students who select the pie or line graph will require other opportunities to develop the knowledge and skills necessary to select the appropriate form of communicating their evidence. Those opportunities could be provided as part of a Maths lesson that is planned for the same time as carrying out this activity. Providing opportunities in another curriculum area demonstrates that certain knowledge and skills are transferable.

The students who selected the bar graph provide the teacher with an opportunity to ask:

  • "Can you explain why you selected it?" During the field trials, some students just knew the correct one but found it difficult to explain their choice. They often responded with easy and more accurate, easier for me to use, and it is the easiest and more clear.
  • These responses provide an opportunity for a coaching question,
  • "What makes a bar graph easy to use, clearer and more accurate?" It will also allow students to share how they decode different graphs.

Discussion of 'continuous data' versus 'discrete data' lends itself to further development of their understanding about science investigations. Students begin to understand that what they change in the investigation will affect their measuring and will also tell them what type of graph that is used. If time (the change) affects the measurements then the graph will probably be a line graph but if the investigation is using different objects (the change) that affect the measurements then a bar graph will probably be the most appropriate. 

Interpreting data (Part 4) is an aspect of procedural knowledge that takes time to develop. Student responses that are 'left blank' or answered don't understand are indicative that more interpretive opportunities should be provided to students that link two sets of data in a representation. This understanding/skill is not confined to science but crosses disciplines. Therefore practice across discipline areas is essential if students are to develop this key competency - Using language, symbols and texts.

Next steps: 
Evaluation of fair test instructions Use any set of fair test instructions and remove an instruction for (a) indicating an appropriate size/amount to use; (b) changing or leaving out a known time element that will affect the results; or (c) taking measurements. Used as a small group activity, the discussion and justification allows students to work together to support their ideas about fair testing (Investigating in science).
Identifying appropriate graphs Use data/evidence from science investigations and other curriculum disciplines. Ask students to justify their selection of a specific graph based on what has been changed in the investigation that affects the measurements.
Interpretation of tables, charts and graphs Small group activities that focus on reading and decoding various tables, charts and graphs. A range of different (cross curricular) tables and graphs could be presented to small groups that allow for decoding and discussion. This activity need not be formal and could be used to complement on-going development and transfer of this skill.
NOTE: This activity could be used with oil instead of water to represent the modelling of oil spills clean-up. Identifying another material could be investigated for its ability to absorb water
The following Building Science Concepts books focus on properties of materials:
  • Ministry of Education (2001). Building Science Concepts Book 5, Fur, feathers, and bark. Wellington: Learning Media.
  • Ministry of Education (2001). Building Science Concepts Book 13, Aluminium. Wellington: Learning Media.
  • Ministry of Education (2003). Building Science Concepts Book 32, Introducing metals. Wellington: Learning Media.
  • Ministry of Education (2003). Building Science Concepts Book 33, Working with metals. Wellington: Learning Media.
  • Ministry of Education (2003). Building Science Concepts Book 48, Fabrics. Wellington: Learning Media.
  • Ministry of Education (2004). Building Science Concepts Book 60, Rubbish. Wellington: Learning Media.
  • Ministry of Education (2004). Building Science Concepts Book 61, Recycling. Wellington: Learning Media.
The following print resources also explore properties of paper.
  • Sneider, C.I. and Barber, J. (1990). Paper Towel Testing – Great Exploration in Maths and Science. Berkeley, CA: Lawrence Hall of Science.
  • Ministry of Education, (1998). Making Better Sense of the Material World. Wellington: Learning Media (pages 91-96).
This activity incorporates aspects of the science capabilities. For more information and ideas go to Introducing the five science capabilities.
 
Other ARB resources relating to properties and fair testing: