Presentation on theme: "Tools of Environmental Science Chapter 2. Objectives List and describe the steps of the experimental method. Describe why a good hypothesis is not simply."— Presentation transcript:
Objectives List and describe the steps of the experimental method. Describe why a good hypothesis is not simply a guess. Describe the two essential parts of a good experiment. Describe how scientists study subjects in which experiments are not possible. Explain the importance of curiosity and imagination in science.
Experimental Method - a series of steps that scientists worldwide use to identify and answer questions. 1) Observation 2) Hypothesis 3) Perform an experiment 4) Organize and analyze data 5) Draw conclusions 6) Repeat experiment 7) Communicate results
Experimental method begins when someone makes an observation and has a questions about what was observed. Why are my plants wilting? Experimental Method
Step #1: Observation A piece of information we gather using our senses – sight, hearing, smell, and touch Can be represented with Descriptions Drawings Photos Measurement Observations lead to questions I see my plants bent over and turning brown. Why is my plant wilting?
Step #2: Form a Hypothesis Hypothesis – a testable idea or explanation that leads to a scientific investigation Used to answer a specific question about an observation My plant is not getting enough water.
Step #3: Experiment A procedure designed to test a hypothesis under controlled conditions Should determine cause and effect relationships I will water one plant on a regular basis and not water the one next to it.
Step #3: Experiments In order to determine cause and effect experiments must have: A single variable that we are testing Ex: water A control group - to serves as the standard of comparison Ex: the plant with no water Experimental group – condition with the new variable Ex: plant that gets water
The independent, or manipulated variable, is a factor that’s intentionally changed by the experimenter. Ex: water The dependent, or responding variable, is the factor that may change as a result of changes made in the independent variable. Ex: health of the plant, degree of wilting All other factors and environmental conditions in the experiment must remain the same. They are the constants. Ex: soil, pot, room temperature Step #3: Experiment
Step #4: Analyze Data Data – gathered information, usually in a numeric form. Data is put into graphs and tables for better understanding
Step #5: Conclusion Determine the results of your study by analyzing their data and comparing the results with their predictions and hypothesis. The plant that was watered did better than the one with no water.
Step #7: Communicate results Your study is not finished until you have shared your results
Correlation Method When experimenting is unethical or impossible to test we can use correlations. Correlation – an association between two or more events Does not prove cause and effect relationships Ex: There is a correlation between TV watching and childhood violence Can you think of other reasons for this correlation?
Scientific State of Mind Curiosity Skepticism – don’t believe everything you are told Openness to new ideas Honesty Imagination and creativity
Section 2 - Objectives Explain how scientists use statistics. Explain why the size of a statistical sample is important. Describe three types of models commonly used by scientists. Explain the relationship between probability and risk. Explain the importance of conceptual models and mathematical models.
Section 2: Statistics and Models Statistics – the collection and classification of data in the form of numbers They help organize data by: Summarizing Characterizing Analyzing comparing
Statistical Vocab Mean – average Probability – the chance that something will happen Sample – a group selected to represent a larger population Risk – the probability of an unwanted outcome Distribution – shown on a graph
What are you afraid of? Rank the following in order from mostly likely to die from to least likely: Venomous bite Airplane crash Drowning Cancer Car accident Falling down Gunshot Fireworks accident Heart disease Lightning
How did you do? Heart disease1 in 5 Cancer1 in7 Car accident1 in 100 Falling down1 in 246 Gunshot1 in 325 Drowning1 in 8,942 Airplane crash1 in 20,000 Lightning1 in 83,930 Venomous Bite1 in 100,000 Fireworks1 in 615,488
Can you name some models? Not of the human type!
Models – representations of objects or systems Physical models – three dimensional, you can touch them. Ex: globe Graphical model – maps, charts, graphs Conceptual model – a verbal or graphical explanation of how a system works or is organized. Ex: atom Mathematical model – equations that represent the way a system or process works. Ex: earths rotation
Section 3 - Objectives Describe three values that people consider when making decisions about the environment. Describe the four steps in a simple environmental decision-making model. Compare the short-term and long-term consequences of two decisions regarding a hypothetical environmental issue.
Section 3: Making Informed Decisions Values – principles or standards we consider important Name some of your values….
Section 3: Making Informed Decisions Decision-making model – a conceptual model that provides a systematic process for making decisions
Section 3: Making Informed Decisions Read the Case Study-page 48-49 and answer questions Section 3 review Pg. 51 # 1&2