Tools of Environmental Scientist Chapter 2

 Scire (latin)  to know What is Science?

1.A body of collected info 2.A human activity with the goal of discovering the how nature works. What is science?

The Experimental Method  Observation is a piece of information we gather using our senses.  Observations are usually the first step in science.

 Fact- A close agreement by competent observers on a series of observations of the same phenomena.  Scientific facts change over time as new information and technology become available. The Experimental Method

 Hypothesis- A testable explanation for an observation.  A hypothesis is more than just a guess. It should make logical sense from what you already know about the situation. The Experimental Method

 Prediction- a logical explanation about what will happen if the hypothesis is correct. The Experimental Method

Experimentation  Experiment- is a procedure designed to test a hypothesis under controlled conditions

 Variable- is the factor of interest. It is the thing that will change in the experiment.  Experimental group- Is the group in the experiment that will experience the experimental change.  Control group- is the group that does not receive any change. Experimentation

 Independent variable- changed variable  Dependent variable- measured variable  If an experiment was run to test to see if mussels will die if exposed to high levels of phosphate in the water, one set of mussels would be grown in a tank with high levels of phosphate and one group would be grown in a tank with normal levels. Which group is the control group? Which is the experimental group? What are the Independent and dependent variables? Experimentation

 Not all experiments are controlled.  Environmental science has to look at many situations that are not in controlled environments like a laboratory. Experimentation

Organizing and Analyzing Data  Data- information that a scientist gathers during an experiment.  Data is typically organized into tables and graphs so that it can be easily understood

Other parts to the Experimental Method  Drawing conclusions- scientist compare the outcome of their data to their original prediction.  Repeating experiments- experiments that can be repeated with the same results by different people in different places are more valid.  Communicating results- scientist publish their results to show others what has been learned.

Correlation Method  When using an experiment to answer a question is impossible or unethical scientist use the correlation method.  Correlations do not always prove cause and effect relationships.

Scientific Habits of Mind  Curiosity  Skepticism  Openness to new ideas  Intellectual honesty  Imagination and creativity

 Law- A hypothesis that has been rigorously tested and has not been contradicted. Explains what will happen but not why.  Theory- A logical explanation for events that occur in nature. Includes laws and hypotheses. Explains the why something happens. Scientific Ideas

Statistics and Models  Statistics is the collection and classification of data in the form of numbers.  Used to summarize, characterize, analyze, and compare data.

Statistics and Models  Mean- (average) is the number obtained by adding up the data for a given characteristic and dividing this sum y the number of individuals.  Distribution- the relative arrangement of the members of a statistical population.

Statistics and Models  Probability- the chance something will happen.  Sample- group of individuals or events selected to represent the population.  The larger the sample size the more accurate the pobability.

 Models- representations of objects or systems.  Physical model- three-deminsional models that you can touch. Statistics and Models

 Graphical Models- maps and graphs are the most common types of graphical models. Statistics and Models

 Conceptual Models- is a verbal or graphical representation of how a system works or is organized. Statistics and Models

 Mathematical models- is one or more equations that represents the way a system or process works.  These models are useful when many variables are involved like predicting weather.  Also, known as computer models. Statistics and Models

Making Informed Decisions Values-principles or standards we consider important.Values-principles or standards we consider important. Science is not good or badScience is not good or bad Society decides good and badSociety decides good and bad

Making Informed Decisions  Decision-making Model- Conceptual model used to help organize information to make decisions.

Making Informed Decisions