Environmental Science

1. Environmental Science Chapter 2 – Review of Methods of Science

2. I. Scientific Methods • A. “Science” comes from the Latin verb scire meaning to know • B. Science is not just something you know but it also something you do

3. c. Experimental Method • i. Observing • 1. An observation is a piece of information we gather using our senses • 2. Use tools to extend the senses (ex. Rulers, microscopes, satellites, etc.) • 3. Can be descriptions, photographs, measurements, etc.

4. ii. Hypothesizing and Predicting • 1. To answer specific questions, scientists may form a hypothesis • 2. Hypothesis = testable explanation for an observation; an educated guess • 3. After forming a hypothesis, you can make a prediction = a logical statement about what will happen if the hypothesis is correct

5. iii. Experimenting • 1. Questions that arise from observations often cannot be answered by making more observations • 2. Experiment = a procedure designed to test a hypothesis under controlled conditions • 3. Should be designed to pinpoint cause and effect relationships

6. 4. Good experiments have 2 essential characteristics • A. Variable = factor of interest • B. Experimental and control groups • i. Experimental group = group that receives the experimental treatment • Ii. Control group = group that does not receive the experimental treatment

7. iv. Organizing and Analyzing Data • 1. Data = information that a scientist gathers during an experiment, often in numerical form • 2. Organizing data into tables and graphs helps scientists analyze data and clearly explain it to others

8. Drawing Conclusions • 1. Decide whether results agree or disagree with hypothesis and predictions

9. vi. Repeating Experiments • 1. Scientists should repeat experiments in order to provide supporting evidence for conclusions • vii. Communicating Results • 1. Publish results

10. II. The Correlation Method • A. When using experiments to answer questions but it may be impossible or unethical, scientists test predictions by examining correlations • i. Correlation = reliable associations between 2 or more events • B. Are useful but do not necessarily prove cause and effect between variables

11. The Correlation Method

12. III. Scientific Habits of Mind • A. Curiosity • B. Habit of skepticism • C. Openness to new ideas • D. Intellectual honesty • E. Imagination and creativity

13. IV. Statistics and Models • A. How scientists use statistics • i. Statistics = collection and classification of data that are in the form of numbers

14. b. Statistics work with populations • i. A statistical population = a group of similar things that a scientist is interested in learning about • Ii. What is the average? • 1. Mean = number obtained by adding up the data for a given characteristic and dividing the sum by the number of individuals • 2. Scientists can easily compare different populations by comparing their means

15. iii. The Distribution • 1. Relative arrangement of the numbers of a statistical population • 2. Normal distribution = bell shaped curve; data are grouped symmetrically around the mean

16. iv. What is the probability? • 1. Probability = the chance that something will happen • 2. Depends on sample size • 3. Sample = group of individuals or events selected to represent the population

17. c. Statistics in Everyday Life • i. Understanding the news • Ii. Thinking about risk • 1. Risk = probability of an unwanted outcome

18. Risk

19. d. Models • i. Are representations of objects or systems • Ii. Physical models • 1. Are 3-D models • 2. Closely resemble the object or system they represent • 3. Ex. DNA

20. iii. Graphical Models • 1. Ex. Maps and charts

21. iv. Conceptual Models • 1. Is a verbal or graphical explanation for how a system works or is organized • 2. ex. Flow chart

22. v. Mathematical models • 1. One or more equations that represents the way a system or process works • 2. Ex. weather

23. V. Making Informed Decisions • A. Environmental – Decision Making Model = a conceptual model that provides a systematic process for making decisions • i. Values = principles or standards we consider important

25. b. How to Use the Model • i. Gather information • Ii. Consider values • Iii. Explore consequences • 1. Positive/negative short term • 2. Positive/negative long term • Iv. Make a decision

26. Should Valley County Set Aside a Nature Preserve?