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 statement about an hypothesis – explains hypothesis – explains what will happen in a what will happen in a specific situation 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 makes it more reliable

7. Communicate Publish 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!