1. CH. 2 Tools of Environmental Science I. Scientific Methods I. Scientific Methods A. The Experimental Method A. The Experimental Method Scientists make discoveries using the experimental method – a series of steps that scientists worldwide Scientists make discoveries using the experimental method – a series of steps that scientists worldwide use to identify and answer questions use to identify and answer questions First step is observing First step is observing

2. 1-Observation 1-Observation – a piece of information we gather using our senses – sight, hearing, smell, and touch 1-Observation – a piece of information we gather using our senses – sight, hearing, smell, and touch -after you observe, you begin to ask questions -after you observe, you begin to ask questions -scientists extend their senses by using rulers, microscopes, even satellites -scientists extend their senses by using rulers, microscopes, even satellites -can take many forms like descriptions, drawings, photographs and measurements -can take many forms like descriptions, drawings, photographs and measurements

3. 2-Hypothesizing and Predicting 2-Hypothesizing and Predicting 2-Hypothesizing and Predicting To answer a specific question, a scientist may form a hypothesis. To answer a specific question, a scientist may form a hypothesis.

4. Hypothesis Hypothesis – a testable explanation for an observation Hypothesis – a testable explanation for an observation -it is more than a guess -it is more than a guess -it should make logical sense and follow from what you already know about the situation -it should make logical sense and follow from what you already know about the situation To test a hypothesis, the students make a prediction To test a hypothesis, the students make a prediction

5. Prediction Prediction – a logical statement about what will happen if the hypothesis is correct Prediction – a logical statement about what will happen if the hypothesis is correct -it is important that the hypothesis can be disproved -it is important that the hypothesis can be disproved -every time a hypothesis is disproved, the number of possible explanations for an observation is reduced -every time a hypothesis is disproved, the number of possible explanations for an observation is reduced -by eliminating possible explanations, a scientist can zero in on the best explanation with more confidence -by eliminating possible explanations, a scientist can zero in on the best explanation with more confidence

6. 3-Experimenting 3-Experimenting 3-Experimenting Experiment – a procedure designed to test a hypothesis under controlled conditions Experiment – a procedure designed to test a hypothesis under controlled conditions -should be designed to pinpoint cause-and – effect relationships -should be designed to pinpoint cause-and – effect relationships -all experiments have 2 essential characteristics -all experiments have 2 essential characteristics 1- a single variable is tested 2-a control is used

7. Variable Variable – the factor of interest Variable – the factor of interest -to test for one variable scientists study two groups or situations at the same time and the variable being studied is the only difference between the two groups -to test for one variable scientists study two groups or situations at the same time and the variable being studied is the only difference between the two groups

8. Groups in an Experiment Experimental group – the group that receives the experimental treatment Experimental group – the group that receives the experimental treatment Control group – the group that does not receive the experimental treatment – the one that says the same Control group – the group that does not receive the experimental treatment – the one that says the same

9. 4-Organizing and Analyzing Data 4-Organizing and Analyzing Data 4-Organizing and Analyzing Data Keeping careful and accurate records is extremely important in science Keeping careful and accurate records is extremely important in science A scientist cannot rely on results that are based on sloppy observations or incomplete records A scientist cannot rely on results that are based on sloppy observations or incomplete records

10. Which is easier to understand?

11. Data Data- the information that a scientist gathers during an experiment – often in numeric form Data- the information that a scientist gathers during an experiment – often in numeric form Graphs are used to display relationships or trends in the data Graphs are used to display relationships or trends in the data -bar graph – useful for comparing the data for several things on one graph -bar graph – useful for comparing the data for several things on one graph

12. Organizing data into tables and graphs helps scientist analyze and explain the data

13. 5-Drawing Conclusions Scientists determine the results of the experiment by analyzing their data and comparing the outcome to their prediction. Scientists determine the results of the experiment by analyzing their data and comparing the outcome to their prediction. Sometimes the conclusion is obvious while other times the conclusion is not so obvious Sometimes the conclusion is obvious while other times the conclusion is not so obvious Using mathematical tools can help scientists determine whether such differences are meaningful or just a coincidence Using mathematical tools can help scientists determine whether such differences are meaningful or just a coincidence Scientists also repeat their experiments Scientists also repeat their experiments

14. 6-Repeating Experiments Although results from a single experiment may seem conclusive, scientists look for a large amount of Although results from a single experiment may seem conclusive, scientists look for a large amount of supporting evidence before they accept a hypothesis supporting evidence before they accept a hypothesis The more often an experiment can be repeated with the same results, the more reliable the results The more often an experiment can be repeated with the same results, the more reliable the results

15. 7-Communicating Results Scientists publish their results to share what they have learned with other scientists Scientists publish their results to share what they have learned with other scientists -publishing a scientific article -publishing a scientific article -article includes the question explored, reasons why the question is important, background information, precise description of how the work was done, the data that was collected, and the scientist’s interpretation of the data -article includes the question explored, reasons why the question is important, background information, precise description of how the work was done, the data that was collected, and the scientist’s interpretation of the data

16. B. The Correlation Method Sometimes questions cannot be studied experimentally Sometimes questions cannot be studied experimentally -what was earth’s climate like 60 million years ago? – we weren’t there -what was earth’s climate like 60 million years ago? – we weren’t there -does smoking cause lung cancer in humans? – experimental testing is unethical -does smoking cause lung cancer in humans? – experimental testing is unethical

17. Correlations Correlations – reliable associations between two or more events Correlations – reliable associations between two or more events -used when testing is impossible or unethical -used when testing is impossible or unethical Correlation studies are useful but do not necessarily prove cause-and-effect relationships between two variables Correlation studies are useful but do not necessarily prove cause-and-effect relationships between two variables

18. Correlation-Rainfall and Tree Ring Width

19. John Snow’s Cholera Spot Map

20. Scientific Habits of Mind C. Scientific Habits of Mind C. Scientific Habits of Mind Good scientists tend to share several key habits of mind, or ways of approaching and thinking about things Good scientists tend to share several key habits of mind, or ways of approaching and thinking about things -curiosity -curiosity -habit of skepticism -habit of skepticism -skeptical – meaning they don’t believe everything they are told -skeptical – meaning they don’t believe everything they are told -leads to questioning of the status quo -leads to questioning of the status quo

21. Scientific Habits of Mind openness to new ideas openness to new ideas -keeps an open mind as to how the world works -keeps an open mind as to how the world works -intellectual honesty -intellectual honesty -a scientist may be convinced their hypothesis is correct even before it has been fully tested, but when an experiment is repeater the results may be different than the first time -a good scientist can admit their hypothesis might be wrong -a good scientist can admit their hypothesis might be wrong

22. Scientific Habits of Mind -imagination and creativity -imagination and creativity -open to new ideas and can conceive of new ideas themselves -open to new ideas and can conceive of new ideas themselves -they can see patterns where others do not or imagine things that others cannot -they can see patterns where others do not or imagine things that others cannot -allows them to expand the boundaries of what we know -allows them to expand the boundaries of what we know

23. II. Statistics and Models II. Statistics and Models II. Statistics and Models Statistics – the collection and classification of data that are in the form of numbers Statistics – the collection and classification of data that are in the form of numbers A. How Scientists Use Statistics A. How Scientists Use Statistics Scientists use statistics to summarize, characterize, analyze, and compare data. Scientists use statistics to summarize, characterize, analyze, and compare data.

24. Statistics For populations, scientists use statistic to describe statistical populations – a group of similar things a For populations, scientists use statistic to describe statistical populations – a group of similar things a scientist is interested in learning about scientist is interested in learning about Statistics are used to group characteristics of individuals within a population by calculating averages, or Statistics are used to group characteristics of individuals within a population by calculating averages, or the mean – the number obtained by adding up the data for a given aspect of a population and dividing the mean – the number obtained by adding up the data for a given aspect of a population and dividing this sum by the number of individuals this sum by the number of individuals

25. The Mean The mean provides a single numerical measure for a given aspect of a population The mean provides a single numerical measure for a given aspect of a population -scientists can compare populations by comparing their means -scientists can compare populations by comparing their means

26. Distribution Distribution – the relative arrangement of the members of a statistical population Distribution – the relative arrangement of the members of a statistical population -the pattern that the bars on a bar graph creates -the pattern that the bars on a bar graph creates -the overall shape of the bars is also part of the distribution – the bell curve indicates a normal distribution -the overall shape of the bars is also part of the distribution – the bell curve indicates a normal distribution

27. Distribution Normal distribution – a bell-curve, is when the data are grouped symmetrically around the mean Normal distribution – a bell-curve, is when the data are grouped symmetrically around the mean Probability – the chance that something will happen Probability – the chance that something will happen -it is usually expressed as a number between 0 and 1 and written as a decimal rather than a fraction Sample size – the number of objects or events sampled -it can be too small to yield an accurate result Sample size – the number of objects or events sampled -it can be too small to yield an accurate result

28. Sample – the group of individuals or events selected to represent the population Sample – the group of individuals or events selected to represent the population Scientists try to make sure the sample they take is large enough to give an accurate estimate for the whole population Scientists try to make sure the sample they take is large enough to give an accurate estimate for the whole population

29. Statistics in Everyday Life B. Statistics in Everyday Life B. Statistics in Everyday Life In the news there are statistics every day In the news there are statistics every day -recognizing and paying attention to statistics will make you a better consumer of information

30. Risk – the probability of an unwanted outcome if you have a 1 in 4 chance of failing a class, the risk is ¼ or.25 the news may show a well-publicized environmental problem but it might not be as statistically important as the news makes us believe the news may show a well-publicized environmental problem but it might not be as statistically important as the news makes us believe The most important risk is the risk of death – most people overestimate the risk of dying from sensational causes, and underestimate the risk from common causes The most important risk is the risk of death – most people overestimate the risk of dying from sensational causes, and underestimate the risk from common causes

31. Risk The same with environmental problems – overestimating sensational environmental problems and underestimating the risk of ordinary ones The same with environmental problems – overestimating sensational environmental problems and underestimating the risk of ordinary ones

33. C. Models Models – representations of objects or systems Models – representations of objects or systems -4 types of models -4 types of models Physical models – three-dimensional models you can touch Physical models – three-dimensional models you can touch -closely resemble the object or system they represent but may be larger or smaller -closely resemble the object or system they represent but may be larger or smaller

34. Graphical & Concept models Graphical models – maps and charts Graphical models – maps and charts -road maps, positions of stars, amount of forest cover in a given area, and the depth of water in a lake Conceptual models – verbal or graphical explanation for how a system works or is organized Conceptual models – verbal or graphical explanation for how a system works or is organized -flow chart -can be diagrams or verbal descriptions or even drawings of how something works or is put together

36. Mathematical models Mathematical models – one or more equations that represents a way system or process works Mathematical models – one or more equations that represents a way system or process works -very useful in cases with many variables -many think because they use numbers they are always right, but people are the ones who interpret the data and write the equations -if the data or equations are wrong, the model will not be realistic and will provide incorrect information -they are only as good as the people building them -they are only as good as the people building them

37. III. Making Informed Decisions III. Making Informed Decisions III. Making Informed Decisions Scientific research is the first step in solving environmental problems Scientific research is the first step in solving environmental problems -many other factors have to be considered such as how will the solution affect people’s lives, how much will it cost, is it ethical? -many other factors have to be considered such as how will the solution affect people’s lives, how much will it cost, is it ethical?

38. Values Values – principles or standards we consider important Values – principles or standards we consider important -examine values to answer the more difficult questions -examine values to answer the more difficult questions

39. A. Environmental Decision-Making Model Decision-making model – is a conceptual model that provides a systematic process for making decisions Decision-making model – is a conceptual model that provides a systematic process for making decisions -can ease the difficulty of forming an opinion on environmental issues -can ease the difficulty of forming an opinion on environmental issues 1-Gather information 1-Gather information 2-Consider values 2-Consider values 3-Explore the consequences 3-Explore the consequences 4-Make a decision 4-Make a decision

40. Decision Making Model