Scientific Method Review

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Scientific Method Review

• Run this PPT show to help you review for your
  midterm.

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• The PROBLEM of an experiment is in the form of a
  ____.
• Question

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• A ______ is an EDUCATED GUESS to the problem of
  the experiment.
• Hypothesis

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• The hypothesis is based on
• background research

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• The ___________ states whether your hypothesis is
  correct or incorrect.
• conclusion

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• What would make the results of an experiment
  carried out by a research team VALID or more
  RELIAABLE?
• The experiment was repeated and the same results
  were obtained each time.
• Use a larger sample size.

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• The ________________does not contain the
  independent variable.
• control group

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• What is MEASURED is known as the ______ variable.
• dependent

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• A new idea that IS TESTED in a scientific experime
  nt is known as the ________.
• hypothesis

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The results of one experiment carried out by a
research team would be considered valid if 1.
the experiment had no control setup2. all
the members of the research team came to
the same conclusion3. the experiment had more
than one variable4. the experiment was
repeated and the same results were obtained
each time
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• Which is the dependent variable in Amelia's
  experiment?
• the number of bean plants in each group
• the amount of water given daily to each plant
• the height of each bean plant
• the amount of fertilizer given to each group of
  bean plants

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• A new idea that is tested in a scientific experime
  nt is known as a(an)
• theory
• hypothesis
• inference
• observation

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• Which statement about the use of independent
  variables in controlled experiments is correct?
• A different independent variable must be used
  each time an experiment is repeated.
• The independent variables must involve time.
• Only one independent variable is used for each
  experiment.
• The independent variables state the problem being
  tested.

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• Why do scientists consider any hypothesis
  valuable?
• A hypothesis requires no further investigation.
• A hypothesis may lead to further investigation
  even if it is disproved by the experiment.
• A hypothesis requires no further investigation if
  it is proved by the experiment.
• A hypothesis can be used to explain a conclusion
  even if it is disproved by the experiment.

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• The first step in the scientific method is
• to state the problem
• experimentation
• to state the hypothesis
• observation

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• An educated guess to the problem of an experiment
  is known as a
• variable
• theory
• hypothesis
• law

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• When performing an experiment, you are testing
  the
• problem
• hypothesis
• data
• conclusion

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• The hypothesis is based on the
• conclusion
• dependent variable
• data collected
• background research

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• Your senses can be used to make a(n)
• observation
• conclusion
• hypothesis
• problem

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• Which statement represents an observation?
• Does the vitamin supplement affect plant growth?
  
• The plants under blue light grew 10cm more than
  plants under yellow light.
• 60 grams of drug X was administered to group A.
  The new drug was not administered to group B.
• I think the vitamin supplement will help pants
  grow taller.

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• Which statement represents the problem of an
  experiment?
• Does the vitamin supplement affect plant growth?
  
• The plants under blue light grew 10cm more than
  plants under yellow light.
• 60 grams of drug X was administered to group A.
  The new drug was not administered to group B.
• I think the vitamin supplement will help pants
  grow taller.

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• Which statement represents a hypothesis?
• Does the vitamin supplement affect plant growth?
  
• The plants under blue light grew 10cm more than
  plants under yellow light.
• 60 grams of drug X was administered to group A.
  The new drug was not administered to group B.
• I think the vitamin supplement will help pants
  grow taller.

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• Beta-carotene supplements have been thought to
  protect against cancer. A study was conducted
  with 39,000 women aged 45 and up. Group A
  received a beta-carotene supplement. Group B did
  not receive the beta-carotene supplement. Their
  health was studied over their lifetime. Cancer
  rates for women taking the beta-carotene
  supplement did not really differ from the cancer
  rates of those women taking the placebo.
• Identify the independent variable.
• Beta-carotene supplement

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• Beta-carotene supplements have been thought to
  protect against cancer. A study was conducted
  with 39,000 women aged 45 and up. Group A
  received a beta-carotene supplement. Group B did
  not receive the beta-carotene supplement. Their
  health was studied over their lifetime. Cancer
  rates for women taking the beta-carotene
  supplement did not really differ from the cancer
  rates of those women taking the placebo.
• Identify the dependent variable.
• Their health

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• Beta-carotene supplements have been thought to
  protect against cancer. A study was conducted
  with 39,000 women aged 45 and up. Group A
  received a beta-carotene supplement. Group B did
  not receive the beta-carotene supplement. Their
  health was studied over their lifetime. Cancer
  rates for women taking the beta-carotene
  supplement did not really differ from the cancer
  rates of those women taking the placebo.
• Identify the control group.
• Group B (did not receive the beta-carotene
  supplement)

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• Beta-carotene supplements have been thought to
  protect against cancer. A study was conducted
  with 39,000 women aged 45 and up. Group A
  received a beta-carotene supplement. Group B
  received a placebo. Their health was studied over
  their lifetime. Cancer rates for women taking the
  beta-carotene supplement did not really differ
  from the cancer rates of those women taking the
  placebo.
• Identify the experimental group.
• Group A (received the beta-carotene supplement)

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• Beta-carotene supplements have been thought to
  protect against cancer. A study was conducted
  with 39,000 women aged 45 and up. Group A
  received a beta-carotene supplement. Group B did
  not receive the beta-carotene supplement. Their
  health was studied over their lifetime. Cancer
  rates for women taking the beta-carotene
  supplement did not really differ from the cancer
  rates of those women taking the placebo.
• Identify 2 constants or controls.
• Gender (all women)
• Amount of food eaten
• Number of women in each group

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• Beta-carotene supplements have been thought to
  protect against cancer. A study was conducted
  with 39,000 women aged 45 and up. Group A
  received a beta-carotene supplement. Group B did
  not receive the beta-carotene supplement. Their
  health was studied over their lifetime. Cancer
  rates for women taking the beta-carotene
  supplement did not really differ from the cancer
  rates of those women taking the placebo.
• How can the results of this experiment be made
  more valid?
• Repeat the experiment.
• Use a larger sample size

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To investigate the effect of a substance on plant
growth, 2 bean plants of the same species were
grown under identical conditions with Substance Z
added to the soil of one of the plants. At the
end of 2 weeks, the plant grown with Substance Z
was 12.5 cm tall. The plant grown without
Substance Z was 12.2cm tall. The researcher
concluded that the presence of Substance Z causes
the plants to grow taller. Identify the
independent variable. Substance Z
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To investigate the effect of a substance on plant
growth, 2 bean plants of the same species were
grown under identical conditions with Substance Z
added to the soil of one of the plants. At the
end of 2 weeks, the plant grown with Substance Z
was 12.5 cm tall. The plant grown without
Substance Z was 12.2cm tall. The researcher
concluded that the presence of Substance Z causes
the plants to grow taller. Identify the
dependent variable. Plant height (how tall the
plant grew)
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To investigate the effect of a substance on plant
growth, 2 bean plants of the same species were
grown under identical conditions with Substance Z
added to the soil of one of the plants. At the
end of 2 weeks, the plant grown with Substance Z
was 12.5 cm tall. The plant grown without
Substance Z was 12.2cm tall. The researcher
concluded that the presence of Substance Z causes
the plants to grow taller. Identify the control
group. The group that did not receive Substance
Z.
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To investigate the effect of a substance on plant
growth, 2 bean plants of the same species were
grown under identical conditions with Substance Z
added to the soil of one of the plants. At the
end of 2 weeks, the plant grown with Substance Z
was 12.5 cm tall. The plant grown without
Substance Z was 12.2cm tall. The researcher
concluded that the presence of Substance Z causes
the plants to grow taller. Identify the
experimental group. The group that received
Substance Z.
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To investigate the effect of a substance on plant
growth, 2 bean plants of the same species were
grown under identical conditions with Substance Z
added to the soil of one of the plants. At the
end of 2 weeks, the plant grown with Substance Z
was 12.5 cm tall. The plant grown without
Substance Z was 12.2cm tall. The researcher
concluded that the presence of Substance Z causes
the plants to grow taller. Identify 2 constants
or controls. Same species Amount of water Amount
of sunlight Temperature
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To investigate the effect of a substance on plant
growth, 2 bean plants of the same species were
grown under identical conditions with Substance Z
added to the soil of one of the plants. At the
end of 2 weeks, the plant grown with Substance Z
was 12.5 cm tall. The plant grown without
Substance Z was 12.2cm tall. The researcher
concluded that the presence of Substance Z causes
the plants to grow taller. How can the results
of this experiment be made more valid? Repeat
the experiment. Use a larger sample size.
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• To test the effect of hormones on plant growth, 6
  potted plant seedlings of the same species were
  measured and then sprayed with a growth hormone.
  After 4 weeks of growth under ideal conditions,
  the plants were measured again.
• How would you set up the control group?
• There should be another group with 6 plants that
  DO NOT receive water.

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• To test the effect of hormones on plant growth, 6
  potted plant seedlings of the same species were
  measured and then sprayed with a growth hormone.
  After 4 weeks of growth under ideal conditions,
  the plants were measured again.
• Identify the independent and dependent variables.
• Independent variable Growth hormone
• Dependent variable Length of the seedling

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• To test the effect of hormones on plant growth, 6
  potted plant seedlings of the same species were
  measured and then sprayed with a growth hormone.
  After 4 weeks of growth under ideal conditions,
  the plants were measured again.
• Identify 2 factors that must be kept constant.
• The amount of water each plant receives.
• The temperature the plants were kept.
• The species of plant used.
• The amount of soil in each pot.

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