Transcript Ch. 2 Notes - Cherokee County Schools

Chapter 2
Section 1 Scientific Methods
Scientific Method
• Observation
• Hypothesis - an explanation based on observations
and can be tested.
– Predictions - statements made in advance
• Experiments
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Chapter 2
Section 1 Scientific Methods
Experimenting
• Good experiments have:
– a single variable - the factor that changes in an experiment
– 2 groups
• experimental group - receives the variable.
• control group - comparison to the experimental group.
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Chapter 2
Section 1 Scientific Methods
Organizing and Analyzing Data
• Data - pieces of information from observation or
experimentation.
• Organizing data into tables /graphs helps scientists
analyze and explain the data
• Graphs display relationships or trends.
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Chapter 2
Section 1 Scientific Methods
Drawing Conclusions
• Scientists determine the results by comparing the
outcome with their hypothesis.
• The more an experiment can be repeated with the
same results, by different people, the more
conclusive it is.
• Scientists publish their results to share what they
have learned with other scientists.
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Chapter 2
Section 1 Scientific Methods
The Correlation Method
• Correlation is the linear dependence between two
variables.
• Example: the width of a tree ring is a good indicator
of the rainfall the tree received that year.
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Chapter 2
Section 1 Scientific Methods
Scientific Habits of Mind
• Curiosity
• skepticism
• openness to new ideas
• intellectual honesty
• Imagination and creativity
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Chapter 2
Section 2 Statistics and Models
How Scientists use Statistics
• Statistics -collection and classification of numerical data.
• mean - average
– provides a single measure for comparison.
• Probability - likelihood that a possible future event will
occur
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Chapter 2
Section 2 Statistics and Models
Distribution
• Distribution - arrangement of the statistics of a
population.
• The graphs of many characteristics form bell-shaped
curves (ex: height, income).
– data is grouped symmetrically around the mean.
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Chapter 2
Section 2 Statistics and Models
Thinking About Risk
• Risk is the probability of
an unwanted outcome.
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Chapter 2
Section 2 Statistics and Models
Models
• Models show the structure or workings of an object,
system or concept.
• Physical Models
– 3D models
– resemble the object they represent, but may be
larger or smaller.
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Chapter 2
Section 2 Statistics and Models
Graphical Models
• Maps and charts
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Chapter 2
Section 2 Statistics and Models
Conceptual Models
• Conceptual models - how a system works or is
organized.
• A flow-chart illustrates what a system contains, how
those contents are organized and affect one another.
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Chapter 2
Section 2 Statistics and Models
Mathematical Models
• Mathematical models are equations that represent
the way system or process works.
• Mathematical models are useful in cases which may
be variable
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Chapter 2
Section 3 Making Informed
Decisions
Values and the Environment
• Values - principles that an individual considers important.
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Chapter 2
Section 3 Making Informed
Decisions
An Environmental Decision-Making Model
• decision-making model - conceptual model that
provides a systematic process for making decisions.
– used to make decisions about difficult environmental
issues.
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Chapter 2
Section 3 Making Informed
Decisions
A Hypothetical Situation (do not write)
• The golden-cheeked warbler population is declining
in Valley County.
• The town of Pleasanton, in Valley County, is growing
rapidly, and much of the new development is
occurring outside the city limits.
• Biologists who have been studying the warbler warn
county officials that if they do not take action, the
state fish and wildlife service may list the bird as an
endangered species.
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Chapter 2
Section 3 Making Informed
Decisions
A Hypothetical Situation (do not write)
• Several groups join
together to propose that
the county buy several
hundred acres of land
where the birds are
known to breed and save
the land as a nature
preserve.
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Chapter 2
Section 3 Making Informed
Decisions
A Hypothetical Situation (do not write)
• The group also proposes limiting development on
land surrounding the preserve.
• The group obtains enough petitions to put the issue
to a vote, and the public begins to discuss the
proposal.
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Chapter 2
Section 3 Making Informed
Decisions
A Hypothetical Situation (do not write)
• People who own property within the proposed
preserve oppose the plan.
• These property owners have an economic interest in
the situation. They believe that they will lose money if
they are forced to sell their land to the county instead
of developing it.
• Other residents do not like the idea of more
government regulations on how private property can
be used.
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Chapter 2
Section 3 Making Informed
Decisions
A Hypothetical Situation (do not write)
• Other landowners support the plan and fear that
without the preserve the warbler will be listed as an
endangered species. Once listed as endangered, the
state will impose a plan to protect the bird that will
require even stricter limits on land development.
• People who have land near the preserve think that
their land will increase in value.
• Many residents also look forward to hiking and
camping in the preserve.
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Your turn to discuss:
– Gather information-what is the problem?
– Consider Values-what are yours?
– Explore consequences-what are negative
outcomes (short and long term)?
– Make a decision-what would you do?
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Chapter 2
Section 3 Making Informed
Decisions
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Chapter 2
Section 3 Making Informed
Decisions
Make a Decision
• As you learn about issues affecting the environments,
use this decision-making model.
• Be sure to:
– consider your values
– weigh the pros and cons
– keep in mind both the short-term and long-term
consequences of your decision.
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