Transcript Tools of Environmental Science

Tools of
Environmental
Science
Chapter 2
Objectives
• List and describe the steps of the
experimental method.
• Describe why a good hypothesis is not
simply a guess.
• Describe the two essential parts of a good
experiment.
• Describe how scientists study subjects in
which experiments are not possible.
• Explain the importance of curiosity and
imagination in science.
Experimental Method -
• a series of steps that scientists worldwide
use to identify and answer questions.
1)Observation
2)Hypothesis
3)Perform an experiment
4)Organize and analyze data
5)Draw conclusions
6)Repeat experiment
7)Communicate results
Experimental Method
 Experimental method begins when
someone makes an observation and
has a questions about what was
observed.
 Why are my plants wilting?
Step #1: Observation
 A piece of information we gather using our
senses – sight, hearing, smell, and touch
 Can be represented with
 Descriptions
 Drawings
 Photos
 Measurement
 Observations lead to questions
 I see my plants bent over and turning brown.
Why is my plant wilting?
Step #2: Form a Hypothesis
 Hypothesis – a testable idea or
explanation that leads to a
scientific investigation
 Used to answer a specific
question about an observation
 My plant is not getting enough
water.
Step #3: Experiment
 A procedure designed to test a
hypothesis under controlled
conditions
 Should determine cause and effect
relationships
 I will water one plant on a regular
basis and not water the one next to
it.
Step #3: Experiments

In order to determine cause and effect
experiments must have:

A single variable that we are testing


A control group - to serves as the
standard of comparison


Ex: water
Ex: the plant with no water
Experimental group – condition with the new
variable

Ex: plant that gets water
Step #3: Experiment
•
The independent, or manipulated variable, is a
factor that’s intentionally changed by the
experimenter.
•
•
The dependent, or responding variable, is the
factor that may change as a result of changes
made in the independent variable.
•
•
Ex: water
Ex: health of the plant, degree of wilting
All other factors and environmental conditions in
the experiment must remain the same. They are
the constants.
•
Ex: soil, pot, room temperature
Step #4: Analyze Data
 Data – gathered information,
usually in a numeric form.
 Data is put into graphs and
tables for better understanding
Step #5: Conclusion
 Determine the results of your
study by analyzing their data and
comparing the results with their
predictions and hypothesis.
 The plant that was watered did
better than the one with no water.
Step #6: Repeat Experiment
 Always repeat your experiement
 WHY???
Step #7: Communicate results
 Your study is not finished until
you have shared your results
Correlation Method
 When experimenting is unethical or
impossible to test we can use
correlations.
 Correlation – an association between
two or more events
 Does not prove cause and effect
relationships
 Ex: There is a correlation between TV
watching and childhood violence
 Can you think of other reasons for this
correlation?
Scientific State of Mind
 Curiosity
 Skepticism – don’t believe
everything you are told
 Openness to new ideas
 Honesty
 Imagination and creativity
Section 2 - Objectives
 Explain how scientists use statistics.
 Explain why the size of a statistical
sample is important.
 Describe three types of models
commonly used by scientists.
 Explain the relationship between
probability and risk.
 Explain the importance of conceptual
models and mathematical models.
Section 2: Statistics and
Models
 Statistics – the collection and
classification of data in the form
of numbers
 They help organize data by:
 Summarizing
 Characterizing
 Analyzing
 comparing
Statistical Vocab
 Mean – average
 Probability – the chance that
something will happen
 Sample – a group selected to
represent a larger population
 Risk – the probability of an
unwanted outcome
 Distribution – shown on a graph
What are you afraid of?
 Rank the following in order from mostly
likely to die from to least likely:
 Venomous bite
 Airplane crash
 Drowning
 Cancer
 Car accident
 Falling down
 Gunshot
 Fireworks accident
 Heart disease
 Lightning
How did you do?
 Heart disease
1 in 5
 Cancer
1 in7
 Car accident
1 in 100
 Falling down
1 in 246
 Gunshot
1 in 325
 Drowning
1 in 8,942
 Airplane crash
1 in 20,000
 Lightning
1 in 83,930
 Venomous Bite
1 in 100,000
 Fireworks
1 in 615,488
Can you name some models?
Not of the human type!
Models – representations of
objects or systems
 Physical models – three dimensional, you
can touch them. Ex: globe
 Graphical model – maps, charts, graphs
 Conceptual model – a verbal or graphical
explanation of how a system works or is
organized. Ex: atom
 Mathematical model – equations that
represent the way a system or process
works. Ex: earths rotation
Class Work
 Ch. 2
 Section 1 & 2 Review
 Page 39 Questions: 1-4
 Page 46 Questions: 1-3
Section 3 - Objectives
 Describe three values that people
consider when making decisions about
the environment.
 Describe the four steps in a simple
environmental decision-making model.
 Compare the short-term and long-term
consequences of two decisions
regarding a hypothetical environmental
issue.
Section 3: Making Informed
Decisions
 Values – principles or standards we
consider important
• Name some of your
values….
Section 3: Making Informed
Decisions
 Decision-making model – a
conceptual model that provides a
systematic process for making
decisions
Section 3: Making Informed
Decisions

Read the Case Study-page 48-49 and
answer questions

Section 3 review Pg. 51 # 1&2