Transcript Tools of Environmental Science

Tools of
Environmental
Science
2-1Scientific Methods
Objectives
1. List and describe the steps of the
experimental method.
2. Describe why a good hypothesis is not
simply a guess.
3. Describe the two essential parts of a good
experiment.
4. Describe how scientists study subjects in
which experiments are not possible.
5. Explain the importance of curiosity and
imagination in science.
Scientists make most
discoveries using the
scientific method.
Steps in the experimental
method
1. Observations
2. Hypothesis and prediction
Hypothesis – a testable explanation for an
observation
Prediction – a logical
statement about an
hypothesis – explains
what will happen in a
specific situation
3. Experiment – procedure designed to
test a hypothesis
Two groups:
 Experimental – test group
 Control – conditions are kept
the same for comparison to
experimental group
 variables cause changes you
observe
Types of variables:
 Independent variable- what
is being manipulated
 Dependent variable- results
from change in the
independent variable; what
you measure
4. Collect and analyze data
-using tables and graphs
5. Conclusion
 analyze data, hypothesis
correct?, sources of error, etc.
 Revise as necessary
6. Repeat it!
makes it more reliable
7. Communicate
Publish
Correlation Method
- Used when questions can’t be
studied experimentally or
ethically
- Uses associations between
events to answer questions
i.e. tree rings and droughts
How to practice good
science
 Be curious
 Be skeptical
 Be open minded
 Be honest about results –
good or bad
 Use your imagination
 Be creative
2-2 Statistics and Models
Objectives
1. Explain how scientists use statistics.
2. Explain why the size of a statistical sample is
important.
3. Describe three types of models commonly
used by scientists.
4. Explain the relationship between probability
and risk.
5. Explain the importance of conceptual and
mathematical models.
How scientists use Statistics
- Collections of data that are in
the form of numbers; Used to
summarize, characterize,
analyze, and compare data
 Used to look at statistical
populations
 Mean - # of individuals/total –
average
 Distribution – relative
arrangement of numbers
i.e. bell shaped curve
 Probability – the chance
something will happen
Sample - Group of
individuals/events selected to
represent the populations
- shouldn’t be too small
How do we use statistics??
 Understanding the news
 Weather predictions
Floods, hurricanes
 Earthquakes
 Sporting events
 Graduations rates
 Thinking about risk
Risk – probability of unwanted
outcome
Models
Represent objects or systems
Types:
 Physical
 Graphical (maps, charts)
 Conceptual (graphical
representation of how system
works – flow charts)
 Mathematical- equations
2-3 Making Informed
Decisions
Objectives
1.Describe three values that people
consider when making decisions about
the environment.
2.Describe the four steps in a simple
environmental decision-making model.
3.Compare the short-term and long-term
consequences of two decisions regarding
a hypothetical environmental issue.
Decision Making Model
 Research
 Consider values (principals
we consider to be important)
 Consider consequences
 Make your decision!