Transcript Scientific Method

Scientific
Method
Jasmine entered the school science fair competition. She
wanted to see if colored light affected plant growth. However,
when several other students repeated Jasmine's procedure,
they all obtained different results than Jasmine's. What do the
different results mean?
A. The other students should design their own experiments
about light.
B. The results will probably be different every time an
experiment is conducted.
C. Jasmine's results should be accepted since she conducted
the experiment first.
D. Jasmine's results should not be accepted because scientific
results should be repeatable.
Sam is conducting an experiment with pendulums; he thinks that more massive
objects will swing faster. He is testing whether the mass of the swinging object has
an effect on how long it takes to make one swing. He tests two different masses and
collects the data shown in the table.
What should Sam do based on these results?
A. Throw out the data because it doesn't support his hypothesis.
B. Do more trials to see if the difference in time really is significant.
C. Conclude that less massive objects always take more time to swing.
D. Conclude that more massive objects always take more time to swing.
1.
Steps to Scientific Method
OBSERVATIONS
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2.
Main Process of Gathering Data
Use this data to come up with……
QUESTIONS
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3.
What do you want to know or find out?
HYPOTHESIS
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4.
Possible Answer to Questions
Must be testable and able to be proven false
DATA COLLECTION & ANALYSIS
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5.
Perform experiment to get data
Analyze data with tables & graphs
MULTIPLE TRIALS (What and Why?)
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6.
Do experiment more than once
Cancels out mistakes
CONCLUSION
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Summarize results; what you learned
Hypothesis correct / incorrect
A Controlled
Experiment
Part of the scientific method
Variables
 A factor that can change. A variable can
change other factors when it changes.
Examples of variables:
-Temperature
-Light
- Open vs. Closed container
-Location
-Time
-Elevation
-Pressure
Independent vs. Dependent
Variables
 The dependent variable is a factor that
changes because the independent variable
changes. However the independent variable is
not changed by the dependent variable.
 Example: Elevation and Boiling temperature of
water. The boiling temperature of water
changes because of changes in elevation.
Changes in the boiling temperature of water do
not change elevation.
Control
-A variable or factor that does not change
in the experiment. It remains constant.
In a Controlled experiment only one
variable is allowed to change at a time.
Everything else remains constant.
Francisco Redi & Spontaneous
Generation
OBSERVATIONS: Flies land on meat that is left uncovered. Maggots appear on the meat.
HYPOTHESIS: Flies produce maggots.
VARIABLES
Covered jars
Uncovered jars
Constants:
jars, type of meat,
location, temperature,
time
After several
days
Independent Variables:
gauze (keeps flies away from
meat)
Dependent Variable:
whether maggots
appear
Maggots appear
No maggots appear
CONCLUSION: Maggots form only when flies come in contact with meat.
Spontaneous generation of maggots did not occur.
Seed Germination Gizmo
(Extension)
Alka-Seltzer Lab
Exit Ticket
1. Colleen waters the plants in her greenhouse once every day. She wants to find out if the plants will grow more leaves if they are watered more
often. She counts the number of leaves on each plant before she starts. She then continues to water half of each type of plant once daily, but she
waters the other half of each type twice a day.
What is the dependent variable in Colleen's experiment?
A.
the type of plant being grown
B.
the number of leaves the plants grow
C.
the amount of light the plants receive
D.
the number of times the plants are watered
2. Christy wants to find out if the birds that visit the bird feeders in her backyard would rather build nests in birdhouses or in trees. She puts a
birdhouse next to the feeder containing sunflower seeds and hangs a feeder containing cracked corn from a tree.
She observes the birds' nesting activities over the next two weeks and records her observations. Which of the following would improve Christy's
investigation?
A.
putting more food in both bird feeders
B.
setting the feeders up closer to each other
C.
putting the same kind of food in both bird feeders
D.
setting up a third bird feeder containing fruit near a bird bath
3. Randy's science teacher is giving a demonstration to show how a metal reacts with different acids. He places a small piece of the metal in each of
three beakers containing a solution of a different acid. He adds a piece of the metal to a fourth beaker that contains only water. What is the purpose
of the fourth beaker?
A.
It ensures that the hypothesis will be correct.
B.
It provides more data to include in a lab report.
C.
It adds an independent variable to the experiment.
D.
It is the control and serves as the basis for comparison.
4. Curtis conducts an investigation to determine which brand of paper towels is the most
absorbent. He records his findings in the table below.
WATER ABSORBENCY OF PAPER TOWELS
What is the test variable (independent
variable) in this investigation?
A.the liquid used
B. the brand of paper towels
C. the amount of water absorbed
D.the time the towels absorbed water
5. The following bar graph shows the population of
bacteria under different temperature ranges.
What can be concluded about the bacteria from
reading this graph?
A.They thrive at exactly 30°C.
B.They cannot tolerate temperatures above 50°C.
C.They prefer temperatures between 20°C and
30°C.
D.They prefer warmer temperatures to cooler
temperatures.