1. Environmental Science
Chapter 2 Notes
“Tools of Environmental Science”

2. Section 1: Scientific Method

3. Parts of the scientific method
1)observations: (quantitative / qualitative)
Information gathered by using the senses.
2) hypothesis: (educated guess)
Testable explanation for an observation.
3) predicting: logical statement about what will happen if the hypothesis is correct.
4) experiment / data collection:
(dependent / independent variable)
Procedure used to test a hypothesis under controlled conditions.
Data: information that a scientist gathers during an experiment (often numeric)
4) Communicating Results:
(peer review before publication) Scientists publish their results to share what they learned with other scientists.
Parts of the scientific method

4. Correlation Method: using the associations between two or more events – used when an experiment cannot.
Graphs: often used by scientists to display relationships or trends in the data. ex. Bar graph (used for comparing data)
Two Types of Observations:
Quantitative: measured or counted – must contain a number. ex. 22 mL or 75° C
Qualitative: descriptive that doesn’t contain a number.
ex. Color , shape , texture
Scientific Method

5. The bar graph below shows the distribution of lengths in a population of dwarf wedge mussels. Use this graph to answer the following question. (X-axis: length in mm ; y-axis: # of mussels)
1. What is the most likely size predictable for a mussel randomly drawn from this population? a mm b. 45 – 49 mm c mm d – 74 mm

6. Parts of an Experiment Variable: the factor of interest.
-scientist usually study two groups or situations at a time.
-the variable studied is the only difference between the groups.
Experimental Group: the group that receives the experimental treatment.
Control Group: the group that does not receive the experimental treatment.
Independent Variable: the variable being tested. The part of the
experiment
that is
manipulated
by the
experimenter.
Dependent Variable: the variable being
measured in
response to
the variable
being tested.
Parts of an Experiment

7. Scientific Method Continued
Conclusion: Is drawn after a scientist analyzes the collected data and is compared to the hypothesis.
Repeating experiments: looking for the reliability of their conclusions.
Organizing and Analyzing Data:
Graphs
Data tables
Graphic
organizers
Scientific Method Continued

8. Question 1: In an experiment, the experimental treatment differs from the control treatment only in the _________ being studied.
a. experiment b. variable c. hypothesis d. data
Question 2: Why is it important to use unbiased methods in scientific research?
a. Unbiased methods are more persuasive to the public.
b. Unbiased methods produce more data that biased methods.
c. Unbiased methods are easier to develop than biased methods.
d. Unbiased methods help scientists to better characterize the
natural world.
Question 1: B Question 2: D
Scientific Method

9. Scientific Habits of Mind
Curiosity: Good scientists are endlessly curious.
Skepticism: Good scientists tend to be skeptical (they don’t believe everything they’re told)
Openness to New Ideas: Always keep an open mind about how the world works.
Intellectual Honesty:
Being willing to accept the hypothesis was not correct if the data doesn’t support it.
Imagination and Creativity: The ability to see patterns where others do not or to imagine things others cannot.
Scientific Habits of Mind

10. What attribute of a skeptic contribute to a good scientific mind?
a. willingness to travel
b. empathetic nature
c. desire to construct experiments
d. continual questioning of observations
Answer: D
Skepticism

11. Section 2: Statistics and Models

12. How Scientist Use Statistics
Statistics: the collection and classification of data that are in the form of numbers.
The Mean:
The number obtained by adding the data for a characteristic and dividing this sum by the number of individuals.
Statistical Population:
A group of similar things that a scientist is interested in learning about.
How Scientist Use Statistics

13. How Scientist Use Statistics
Distribution: the relative arrangement of the members of a statistical group.
bell-shaped curve:
(normal distribution) the data are grouped symmetrically around the mean.
What is the Probability
Probability: The chance that something will happen.
Sample: A group of individuals or events selected to represent the population.
Sample Size: the number of objects or events sampled.
How Scientist Use Statistics

14. Statistics and Models Models Risk: the probability
of an unwanted outcome. Most people overestimate the risk of sensational environmental issues
(ex. radioactive waste) and underestimate the risk of ordinary issues
(ex. Global climate change and water pollution)
Models: representations of objects or systems.
4 Types of Models
Physical Models:are 3-D models you can touch.
Graphical Models:maps and charts.
Conceptual Models:a verbal or graphical explanation of how a system works or is organized. (flow-chart)
Mathematical Models:
equations that represent the way a system or process works.
(Climate model of Earth)
Statistics and Models

15. Section 3: Making Informed Decisions

16. Making Informed Decisions
Decision-Making Model
Values
Decision-Making Model
Is a conceptual model that provides a systematic process for making decisions.
How to Use It:
Gather Information
Consider Values
Explore Consequences
Make a Decision
Values: principals or standards we consider important.
Making Informed Decisions

17. Values That Affect Environmental Decision Making
Aesthetic: what is beautiful or pleasing.
Economic: the gain or loss of money or jobs.
Environmental: the protection of natural resources.
Educational: the accumulation and sharing of knowledge.
Social/Cultural: the maintenance of human communities and their values and traditions.
Recreational: human leisure activities
Values That Affect Environmental Decision Making