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

2. Section 1: Scientific Method 2

3. Parts of the scientific method 3 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.

4. Scientific Method Correlation Method : using the associations between two or more events – used when an experiment cannot be performed. 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 4

5. 1. What is the most likely size predictable for a mussel randomly drawn from this population? a. 40 - 44 mmb. 45 – 49 mmc. 50 - 54 mmd. 70 – 74 mm 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)

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. 6

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

8. 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. 8

9. Section 2: Statistics and Models 9

10. How Scientist Use Statistics Statistics: the collection and classification of data that are in the form of numbers. It is used to analyze data. Statistical Population: A group of similar things that a scientist is interested in learning about. Must be large enough to effectively represent the whole population. The Mean : The number obtained by adding the data for a characteristic and dividing this sum by the number of individuals. 10

11. How Scientist Use Statistics What is the Probability Distribution: the relative arrangement of the members of a statistical group. bell-shaped curve: (normal distribution) the data are grouped symmetrically around the mean. 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. 11

12. Statistics and 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 (Climate model of Earth) 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. Best used with multiple variables. 12

13. Section 3: Making Informed Decisions 13

14. Making Informed Decisions Values Decision-Making Model Values: principals or standards we consider important. Decision-Making Model Is a conceptual model that provides a systematic process for making decisions. How to Use It:  Gather Information  Consider Values *Pros/cons *Long/Short Term  Explore Consequences  Make a Decision 14

15. 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 Ethical: deciding whether something is right or wrong based on your morals. 15