Scientific Methods

Essential Question: Introduction to Science

How does science apply in my everyday life?

What is Science?

What is Science? (cont.)

• Science – systematic knowledge of the physical or material world gained through observation and experimentation • from the Latin word scientia, which means knowledge

• Science studies natural patterns.

2. Science explains the natural world; explanations can change over time. 3. Scientists investigate nature by observation, experimentation, or modeling.

1. Science is classified into three main categories: life science, Earth science, and physical science: sometimes a scientific study will overlap the categories

Scientific Methods • Scientific method - organized set of investigation procedures 1. State a problem. 2. Gather information. 3. Form a hypothesis or educated guess based on knowledge and observation.

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4. An experiment with variables is a common way to test a hypothesis. a) A dependent variable changes values as other variables change b) An independent variable is changed to determine how it will affect the dependent variable. c) A variable that does not change when other variables change is a constant. d) A control is the standard to which test results can be compared.

Essential Question: • How does science apply in my everyday life? Science teaches problem-solving skills that can be used every day.

5. Analyze data from an experiment or investigation. 6. Form a conclusion based on the data. 7. Reduce bias by keeping accurate records using measurable data, and repeating the experiment.

A Model Scientific Method State the problem Modify hypothesis

Gather information Form a hypothesis Test the hypothesis

Repeat several times

Analyze the data Draw conclusions Hypothesis not supported

Scientific Methods

Hypothesis supported

Scientific Methods in Action

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Models • Models represent ideas, events, or objects and can be physical or computerized.

Terminology • • • • • • • •

Hypothesis Experiment Dependent Variable Independent Variable Constant Control Theory Scientific Law

Scientific Theories and Laws • A theory is an explanation based on many observations and investigations. • A scientific law is a statement about something that always seems to be true.

Review: Variables • Independent and dependent variables are related to one another. • The Independent part is what you, the experimenter, changes or enacts in order to do your experiment. • The dependent variable is what changes when the independent variable changes - the dependent variable depends on the outcome of the independent variable.

Review: Variables

Review: Variables

• For example, if you open a faucet (the independent variable), the quantity of water flowing (dependent variable) changes in response-- you observe that the water flow increases.

• Controlled variables are quantities that a scientist wants to remain constant. • For example, if we want to measure how much water flow increases when we open a faucet, it is important to make sure that the water pressure (the controlled variable) is held constant.

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Review: Variables • Independent –What is the experimenter changing?

• Dependent –What is being investigated/measured/ observed?

Review: Constant and Control • Constant- factors that are kept the same • Control- group that the results of the experimental group can be compared to. It is a standard.

Section Assessment 1. What is the first step a scientist usually takes to solve a problem? 2. What is the dependent variable in an experiment that shows how the volume of gas changes with changes in temperature? 3. Explain why a control is needed in a valid experiment. 4. How is science different from technology?

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