The Scientific Method

The Scientific Method

Chem Comm

​Unit 0 Day 5

​The Scientific Method

​Science: "a collection of knowledge gained through observation and experimentation"

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​Science is a Method of Learning About the World

​Step One: Observation & Inference (or Question)

​Observation: Something you notice using your senses

​"This hallway smells like burnt food"

​"This plant is not growing very well"

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​Inference: a reasonable guess

​"Someone is cooking in class today"

​(Is the foods class cooking today?)

​"I think this plant needs more sunlight"

​(Do plants need sunlight to grow?)

​Step Two: Research and Hypothesis

​Hypothesis: a logical, testable statement that is based on evidence

​"The foods room at the end of the hallway is cooking today"

​"Plants need a certain amount of sunlight in order to grow"

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​Step Three: Experiment

​A scientific experiment must have controls and variables

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​Control: The things that stay the same in your experiment

​Independent Variable: The thing that you change in the experiment

​Dependent Variable: The thing that happens in the experiment (what you are measuring)

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​You only want one independent variable in your experiment; everything else should be controlled.

​Step Four: Analysis and Conclusion

​After your experiment is completed, ask yourself these questions:

​*Is there a pattern in the data?

​ If yes, that's probably a good sign!

​ If no, your experiment may need to be changed

​*Does the data support my hypothesis?

​ If yes, your hypothesis is probably correct.

​ If no, you may need to re-work your hypothesis and experiment again.

Signs of a Good Experiment

​Good Experiments are Repeatable: You should be able to get the same results every time you complete an experiment-- if not, your experiment is probably not valid.

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​Good Experiments Have Lots of Data: If you have a small number of samples it is harder to prove that a result wasn't just random chance.

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​Good Experiments Have Strong Correlation: If you graph your data, there should be an obvious trend

Multiple Select

You want to measure how much sunlight a plant needs in order to grow. To do this, you take three plants and give them no light, 5 hours of light, and 10 hours of light each day for a week. Every day you measure how much the plant has grown.

Which of the following should be controls in this experiment?

• The type of plant you use

• How tall the plants grow

• The amount of sunlight you give each plant

• The amount of water you give each plant

• The temperature of each plant

Multiple Select

You want to measure how much sunlight a plant needs in order to grow. To do this, you take three plants and give them no light, 5 hours of light, and 10 hours of light each day for a week. Every day you measure how much the plant has grown.

Which of the following is/are the independent variable in this experiment?

• The type of plant you use

• How tall the plants grow

• The amount of sunlight you give each plant

• The amount of water you give each plant

• The temperature of each plant

Multiple Select

You want to measure how much sunlight a plant needs in order to grow. To do this, you take three plants and give them no light, 5 hours of light, and 10 hours of light each day for a week. Every day you measure how much the plant has grown.

Which of the following is/are the dependent variable in this experiment?

• The type of plant you use

• How tall the plants grow

• The amount of sunlight you give each plant

• The amount of water you give each plant

• The temperature of each plant

Multiple Choice

What is the following statements is a hypothesis?

• Plants need sunlight.

• The plant sitting in the shade is dead.

• The plant that got 10 hours of sunlight grew the most.

• The plant that gets 5 hours of sunlight will show the most growth.

Multiple Choice

What is the following statements is a conclusion?

• Plants need sunlight.

• The plant sitting in the shade is dead.

• The plant that got 10 hours of sunlight grew the most.

• The plant that gets 5 hours of sunlight will show the most growth.