Investigation Sequence

Title

Evidence

Written by:

Andrea Hall and Jaki Thomas

                Date

 

Focus Questions

What is evidence?
What use does evidence have in the scientific method?
Why is it important to have solid evidence?

Concepts

Content: Earth, Physical, & Life

Light can be reflected by a mirror, refracted by a lens, or absorbed by the object.
Intensity (volume) of a sound is related to the amount of energy used to create the sound.
Insulators are slow conductors of heat.
Rocks are made of minerals; each mineral has certain hardness.
Mold is a fungus; different environments are conducive to mold growth.

Cross cutting concepts

Evidence is something that is observed and can be used to understand what is happening and make predictions about future changes.
Evidence is collected through observation.
Scientists must collect a great deal of evidence in order to support their experimentations.
Solid evidence provides credibility.

Science Practice

Evidence is collected as a result of inquiry.
A single example can never prove something true.
I should always seek good reasons for what I think is happening.

Personal, Social, Technology, Nature of Science, History

It is helpful to try to determine in advance how ideas and inventions will affect other people.

Background information

 

 

Activity Sequence

1. Light Absorption
2. Catch a Wave!
3. Insulator Tests
4. Rock Hardness
5. Stopping Mold Cold
6. Taste Regions of the Tongue

Activity Descriptions

Activity One
Light Absorption
Materials: thermometers, heat lamp, white paper, black paper, paper, and pencil for each group.
Procedure:
1. Ask students if they dressed in different colors it would cause them to be warmer or colder. Ask them to support their answers with reasons and evidence.
2. Ask them what would happen if they wrapped two thermometers in two different colors of paper.
3. Ask them if there is a difference in wrapping or just placing the paper in front of the thermometers.
4. Ask how they could support their answers/predictions. Lead them to doing an experiment and collecting evidence.
5. Prop thermometers about 20 cm apart, facing the same direction.
6. Record the temperature on each thermometer.
7. Put sheet of white paper in front of one thermometer and black paper in front of the other. Repeat the same procedure only wrap two thermometers in the same kinds of paper.
8. Shine heat lamp on each sheet of paper equally from 40-50 cm away.
9. After two minutes, check and record temperatures again.
10. Repeat two more minutes and record again.
11. Compare changes in first and last temperature readings.
12. Ask. What can you say about the effect of color in this activity?
13. How can you support your answers with evidence? What did you learn about experimenting, reasoning, and evidence?
14. How could this help you outside of school?


Activity Two
Catch a Wave!
Materials: spoon, two tin cans, plastic wrap, sugar sprinkles, cotton ball, thread, tuning fork, and jump rope for each group.
Procedure:
1. Ask. What is sound? How does it move? Discuss how sound moves.
2. Ask students if sound waves can cause objects to move.
3. Ask how they could support their answers/predictions. Lead them to doing an experiment and collecting evidence.
4. Set up three stations:
5. Station One: Tin Can
a. One can covered in plastic wrap and sprinkle sugar on top of plastic wrap.
b. Bang spoon against bottom of other can while holding it near the top of the first can.
c. Collect evidence about what happens to the sugar.
d. Ask: Does a loud bang have the same results as a soft bang.
6. Station Two: Tuning Fork
a. Hang cotton ball on a thread near a tuning fork.
b. Vibrate the tuning fork.
c. Record evidence about what happens to each object.
7. Station Three: Jump Rope
a. Have partners hold ends of jump rope.
b. One partner hold one end still while the other partner moves their end up and down.
c. Ask: How can you increase the number of wavelengths? Does it take more energy to make fast waves or slow waves?
8. Let students rotate through each station and explore.
9. Ask if the evidence they found supports the idea that sound waves move.
10. Ask for other situations where they have seen sound cause movement (speakers on electronic equipment, vibrations of objects or walls).


Activity Three
Insulator Tests
Materials: several small identical cans with lids (at least two for each group), different insulating materials, such as wool, cotton, foil, packing peanuts, carpet, newspaper, string and scissors, tape, measuring cup, thermometer, stop watch, paper and pencil.
Procedure:
1. Tell students to think about their lunch or when they went on a picnic. What did you do to keep things hot/cold? This is called insulating.
2. Have students predict what materials are the best insulators.
3. Wrap each material around a can and secure with string or tape, whichever is best. Try to use similar thicknesses of material.
4. Leave one can unwrapped as the control.
5. Fill each container, including the control can, with the same amount of hot water (water must be same temperature in each can).
6. Take the temperature of water in each can every minute. Record results.
7. Continue doing this until the temperature stays steady. Record results.
8. Prepare a way to present your evidence (graph, chart, etc.).
9. Bring the class back together and have them share their data.
10. Where else is insulation used in our lives?
11. Are there ways we can improve our lunch box insulation?


Activity Four
Rock Hardness
Materials: eight rocks per group, magnifying lenses, pennies, knives, steel fingernail file, diamond.
Procedure:
1. When people say something is "as hard as a rock," what are they actually saying? How hard are rocks? Are some rocks harder than others?
2. Ask how they could support their answers/predictions. Lead them to doing an experiment and collecting evidence.
3. Label each rock with a letter from A to H.
4. Students examine the rocks with magnifying lenses and record colors.
5. Perform scratch tests using fingernail, penny, knife, file, and diamond.
6. Record evidence on chart.

Rock
A
B

C

D
E
F
G
H
Rubbing with finger
Fingernail
Penny
Knife
Steel File
Diamond


7. Use evidence to order rocks according to hardness.
8. Bring the class back together.
9. Ask how can you support your answers with evidence?
10. What did you learn about experimenting, reasoning, and evidence?
11. How could you use what you learned?
12. How do scientists use what you learned?


Activity Five
Stopping Mold Cold!
Materials: bread, plastic bags, water, access to refrigerator and warm, dark place.
Procedure:
1. Ask students if they have ever seen moldy food in their kitchen.
2. What places is mold more likely to develop? Which foods grow mold more quickly?
3. Ask how they could support their answers/predictions. Lead them to doing an experiment and collecting evidence.
4. Create four environments:
5. Environment One:
a. Place dry bread in plastic bag and tie it closed.
b. Place the bag in a refrigerator or cold place.
6. Environment Two:
a. Lightly spray bread with water and bag it.
b. Place the bag in refrigerator or cold place.
7. Environment Three:
a. Place dry bread in a plastic bag.
b. Place bag in a warm, dark place.
8. Environment Four:
a. Lightly spray the bread with water and place in a bag.
b. Place bag in a warm, dark place.
9. After one week, compare results and record evidence of mold growth.
10. Order the test breads from the fastest mold grower to the slowest mold grower.
11. Ask: What kind of host does mold like?
How does mold change its environment—what does it feed on?
Where would you put food that you don’t want to mold?
How can you use this information?
How would a scientist use this information?


Activity Six
Taste Regions of the Tongue
Materials: a variety of food samples (one set for each group), paper cups for each food, toothpicks, blindfolds, water, and diagram of regions of the tongue, chart paper and markers.
Procedure:
1. Ask what kinds of tastes are there (sweet, salty, bitter and sour).
2. Ask students what helps them taste.
3. Talk about different regions of the tongue.
4. Ask. Do these regions of the tongue really only taste specific tastes?
5. Ask how they could support their answers/predictions. Lead them to doing an experiment and collecting evidence.
6. Put students in groups of two.
7. One student is blindfolded first.
8. Using a toothpick, place a small amount of one type of food on bitter region of tongue.
9. Partner judges the taste with mouth still open so food sample is not spread to other regions of the tongue.
10. Taste judgment should indicate strength or weakness as well as type (bitter, sour, salty, or sweet).
11. Partner rinses mouth with water and continues with same type of food on other taste regions of tongue.
12. Record taste judgment each time.
13. Repeat procedure with other food types.
14. Trade places and repeat entire procedure.
15. Analyze evidence to determine whether some regions of the tongue are more sensitive to taste than other regions.
16. Make a chart showing your findings.
17. Recent studies have shown that there are no taste regions of the tongue and that all regions of the tongue can taste all flavors. Does our evidence found today support or refute that finding?
18. For each of the following questions also ask if they can give an example.

Questions:
What have you learned?
What have you learned about how scientists do science?
How important is evidence?
How is evidence collected?
How is it used?
Does one example make us believe we understand something?
Is it helpful to anticipate what might happen with an experiment?
Is it sometimes not helpful to anticipate what might happen with an experiment?
Do you enjoy learning?
Do you enjoy being scientists?

Dr. Robert Sweetland's notes