Paper Wicks

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Paper Wicks

• Identifying, Manipulating and Controlling
  Variables

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Paper Wicks
At the heart of the scientific process is the
effort to explore the influence of variables upon
a phenomenon. This is done by (1) identifying
possible factors that might influence the
phenomenon, then by (2) attempting to hold all
factors constant except one, which is
systematically changed, then by (3) concluding
that any changes in the overall phenomenon must
be result of changes in the manipulated
variable. It is important to recognize that just
because a variable can be identified it does not
follow that it must be influential.
Assigning importance to obvious but not
influential variables is common for non-skeptical
thinkers and a typical component of scams.
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Paper Wicks
In this activity we will explore the variables
that might influence the way construction paper
soaks up water. A construction paper strip when
suspended into water will work as a wick and draw
water up the length of the strip. Through
manipulating the variables we will determine
which ones will influence the wickability of
the strip.
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Materials Needed

• A shallow container.
• Several different colored sheets of construction
  paper.
• 7 or 8 plastic soda straws.
• 4 pieces of modeling clay
• 2 straight pins.
• Cellophane tape.
• Scissors
• Writing materials.

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Step 1

• Use a straight pin to join 2 straws together.
• Stick the long end of the straws into the clay so
  the pieces will stand. These will serve as legs.

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Step 2

• Join three straws together by pinching the end of
  one straw and sliding it into the opening of
  another.
• Place this cross piece over the two sets of legs.
• The dish must fit between the legs.

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Step 3

• Add water to the dish until it is about 1/2 full.

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Step 4

• Cut strips of construction paper that are about 3
  cm wide by 12 cm long.
• Add a piece of tape to one end.
• Tape the strip of paper to the cross piece.

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Step 4, continued

• Return the cross piece to the legs.
• Your strip of paper should now be able to hang
  down into the dish below.

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Step 5

• Examine the construction paper. What variables
  might be involved in the phenomenon (construction
  paper acting as a wick)?
• Make a list of them.

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Step 6

• Does your list contain
• color of the paper?
• width of the paper strip?
• temperature of the water?
• others?

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Step 7

• Try this experiment that allows you to test the
  influence of color on the rate at which the water
  will wick up the paper strips.
• What variables are being controlled?
• What do you expect will happen in this test?

To listen to while you set up the experiment.
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Step 7, continued

• This picture shows three different strips after
  one minute.
• Does there appear to be a difference?
• What do you think will happen with time?

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Step 8

• Heres another experiment.
• What variable is being tested?
• Which one(s) are being controlled?
• What do you predict will happen here?

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Step 9

• Design and conduct two experiments with paper
  wicks. Include the following
• variable to be tested
• variables to be controlled
• Report the results of your experiments to the
  class website.

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Relax a little while. This activity is over.