The Scientific Method C1L1CP1 How do scientists work?
I will know the parts of an experiment and be able to use them. Objectives I will be able to list and describe the steps of the scientific method. I will know the parts of an experiment and be able to use them. I will be able to apply the scientific method to science problems. I will be able to design a controlled scientific experiment.
How does the process of scientific investigation work? Science begins with an observation. This is the process of gathering information about events or processes in a careful, orderly way.
How does the process of scientific investigation work? Scientists use a series of procedures called the scientific method (also referred to as scientific inquiry).
an organized way of finding a workable solution to a problem THE SCIENTIFIC METHOD an organized way of finding a workable solution to a problem
Steps of the Scientific Method Define the problem (Question) Form a hypothesis Test the hypothesis Classify and analyze the data Choose and verify the answer (conclusion) Communicate results
(1) Define the problem This process often begins with a problem or question about an observation.
Questions Questions come from experiences that you have and from observations and inferences that you make.
Some questions cannot be investigated by science. Does my dog eat more food than my cat? Which makes a better pet – a cat or a dog?
(1) Define the problem problem: a question that may be answered by the use of the scientific method The problem must be observable, measureable, and repeatable. Background research Limit or define the problem
(2) Form a hypothesis hypothesis: a simple, testable statement about the answer to a problem; a possible solution; an educated guess (a prediction that can be tested)
(3) Test the Hypothesis A scientist will then gather evidence that will either support or disprove the hypothesis. This is done one of two ways: • by conducting an experiment • by conducting a survey
(3) Test the Hypothesis This information (evidence) is called data. data: pieces of information; the information gathered from making observations. (facts, figures, and other evidence gathered through observations) Data must be measured and recorded accurately.
Types of Data Quantitative data are: numbers - obtained by counting or measuring. Qualitative data are: descriptions and involve characteristics that cannot be counted.
What’s in an Experiment? Independent variable dependent variable constants Control group & Experimental group
Example Experiment You wonder if using miracle grow on a plant really causes it to grow better.
Variables are factors or conditions that can vary.
Controlled Experiment In a controlled experiment, you try to control all the variables of two or more groups.
Independent Variable a factor that affects the result of an experiment (also known as experimental variable or manipulated variable)
Dependent Variable The dependent variable is the one observed during the experiment. The dependent variable is the data we collect during the experiment.
Examples of the two types of variables: Independent Variable Dependent Variable Hours Worked Amount of Money Earned Total Calories Consumed Total Weight Gain Number of Assignments Completed Homework Grade
Examples of variables:
Example Experiment You would set up a control group and an experimental group to perform the experiment and gather data.
Types of Groups in a Controlled Experiment Experimental Control
the group that is exposed to the Independent variable Experimental Group the group that is exposed to the Independent variable The experimental group shows the effect of the variable that is being tested.
Control Group the group, in an experiment, that is not exposed to the Independent variable A control is the standard to which the outcome of a test is compared. The control group serves as the comparison. It is the same as the experiment group, except that the one variable that is being tested is removed.
Survey a set of observations that are made to determine what is a common practice in a particular area
(4) Classify and analyze the data classify: arranging data so relationships can be seen
Classify often involves grouping or sorting the data (making a chart or table) which makes answers easier to find Graphs can reveal patterns or trends in data.
(4) Classify and analyze the data analyzing: determining whether a set of data supports a hypothesis
(5) Choose and Verify the Answer (conclusion) Once an answer is chosen, it must be verified.
How do you verify the answer? By gathering additional data through experiments or surveys. The more data that is found to support the answer, the more likely it is that the answer is valid.
Proving vs Verifying Proving and verifying are NOT the same. A scientist can never completely prove an answer. Why? Because it is based on observations done by humans who make mistakes.
A workable answer is one that can be used. Predict outcomes A workable answer is one that can be used.