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Explore the steps involved in conducting a scientific experiment, including observing, questioning, researching, hypothesizing, designing experiments, and analyzing data. Learn how to develop hypotheses, identify variables, and create experimental and control groups. Discover ways to collect, organize, and interpret data in environmental science investigations.
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Chapter 2.2 Skills and Methods Environmental Science 2012
Objectives • Describe the steps involved in conducting a scientific experiment
Bell Ringer • List steps that you know that make up the scientific method:
The Scientific Method • The __________ method does not have to go in _______ • The exact steps of the scientific method may vary, but all good scientific investigations have _____________ _____________
Observing and Questioning • Observations • Can be made directly with the _________ or with the help of ___________
Observing and Questioning • Observations are followed by a question • The ____________ is based on something that was ____________________ • Example: you observe that people who work in a particular building often become sick and you ask why • What is the observation? • What is the question? • Can you think of a hypothesis?
Researching • An ______________ step in solving a scientific investigation is to find out what __________ have already ___________ about the topic • Others ______________ can save you steps or your ______________ may have already been proven or disproven • Do you think scientists repeat experiments on purpose?
Hypothesizing • The next step is to develop a hypothesis • Hypothesis: _________ for an ____________ • Example: • Observation: You notice that grass does not grow in certain parts of a lawn • Question: Why does grass not grow in this area? • Hypothesis: • ____________________________________________ • Only ______ hypothesis must be chosen to investigate in an experiment
Hypothesizing • Observation: You notice that grass does not grow in certain parts of a lawn • Question: Why does grass not grow in this area? • Hypothesis: The area is too shady. • Now we can make a prediction: • _____________: states what the results of the experiment will be if the hypothesis is ___________ • Prediction: • ____________________________________________
Designing an Experiment • ___________ are used to test ____________ • The experiment will either: • ______________ the hypothesis • Not support the hypothesis: can think of a new hypothesis and ____________
Variables • ____________: any factor that affects the outcome of an experiment • An experiment should only test ______ variable at a time • Why? • Example: grass example • If we test the variables of the amount of water and sunlight we will not know which variable is actually affecting the grass
Experimental and Control Groups • _____________: has all of the factors that were there when the original observations were made • ____________________: has all of the factors that were there when the original observations were made and an additional variable • Grass example: • Hypothesis: the grass died because there was no water • ____________________: same conditions as original observations • __________________________: same conditions as original observations and the addition of water
Experimental and Control Groups • Independent Variable: variable being _______ • ______________ • X-axis of graph • Dependent Variable: the variable being __________________ • _______________________ • Y-axis of graph
Collecting, Organizing, and Analyzing Data • Scientists collect _____ on the results of the _____________ and the steps they took to conduct the experiment • There are many ways to display data • __________ • __________
Collecting, Organizing, and Analyzing Data • Once data has been ______________, must decide what the results mean normally through a written ________________ that comments on the _______________________
Collecting, Organizing, and Analyzing Data • The last step is to _________ their scientific work with others • Scientist’s can communicate through: • _________________________ • Publish reports of conclusions in ___________________ • _________________________
Review • Come up with the following for the observation that flowers sitting in the bathroom are not growing. • Question: • Hypothesis: • Prediction: • Design of experiment: • Experimental group: • Control group: • Independent variable: • Dependent variable: