The Scientific Method and Experimental Design

The Scientific Method and Experimental Design

by Tony Robinson

​The Scientific Method:

• ​Has been used since ancient times.

• ​First mentioned in writing by Sir Francis Bacon (great name) around 1600.

• ​Developed so that every scientist could produce results that were repeatable by others questioning their validity.

Multiple Choice

Stephen predicted that seeds would start to grow faster if an electric current traveled through the soil in which they were planted.

• Recognize the Problem

• Form a Hypothesis

• Test the Hypothesis with an Experiment

• Draw Conclusions

Multiple Choice

Susan said, “If I fertilize my geranium plants, they will blossom.”

• Recognize the Problem

• Form a Hypothesis

• Test the Hypothesis with an Experiment

• Draw Conclusions

Multiple Choice

Rene grew bacteria from the mouth on special plates in the laboratory. She placed drops of different mouthwashes on bacteria on each plate.

• Recognize the Problem

• Form a Hypothesis

• Test the Hypothesis with an Experiment

• Draw Conclusions

Multiple Choice

Bob read about growing plants in water. He wanted to know how plants could grow without soil.

• Recognize the Problem

• Form a Hypothesis

• Test the Hypothesis with an Experiment

• Draw Conclusions

Multiple Choice

Kim’s experiment showed that chicken egg shells were stronger when she gave the hen food to which extra calcium had been added.

• Recognize the Problem

• Form a Hypothesis

• Test the Hypothesis with an Experiment

• Draw Conclusions

​OBSERVE / QUESTION

​- Look around you and observe the natural world!

​- Then question what you see.

​- Why is the sky blue?

​- Why is TROB bald?

​- Why is Tom Brady so good at football?

​- THE FOUNDATION OF SCIENCE IS CURIOSITY!!!

​RESEARCH

• ​Once you have identified the problem or asked a question you need to do some background research on the subject.

• ​EXAMPLE PROBLEM:

  • ​Do mice grow larger if given vitamin C?

• ​EXAMPLE RESEARCH:

  • ​Learn about what mice need to grow, and vitamin C's effect on growth.

​Form a HYPOTHESIS

• ​A hypothesis has 3 parts.

  • ​IF

  • ​THEN

  • ​BECAUSE

• ​EXAMPLE:

  • ​If mice are given vitamin C then they will grow larger because vitamin C increases the synthesis of collagen, which is the most abundant protein in the body.

Open Ended

Write a hypothesis for this question:

What amount of sunlight makes a daisy grow best?

Open Ended

Write a hypothesis for this question:

Which size of rock is best for skipping?

​EXPERIMENT

• ​Develop an experiment to test your hypothesis.

• ​NEEDS 3 PARTS:

  • ​INDEPENDENT VARIABLE

    1. ​What YOU are changing

  • ​DEPENDENT VARIABLE

    • ​What you are measuring

  • ​CONSTANTS

    • ​What has to stay the same so you are sure the results are because of the Ind. Var.

​EXAMPLE:

​- Independent Variable: Amount of Vitamin C given to mouse

​- Dependent Variable: Mass of mouse.

Poll

What would the CONSTANTS be in this experiment?

• Type of Mouse

• Amount of Food

• Amount of Water

• All of the options

​TEST THE HYPOTHESIS

• ​Look at the results of your experiment.

• ​Did the results PROVE your hypothesis correct?

• ​If yes.....move on to draw conclusions.

• ​If no.....make a different hypothesis and re-test.

​DRAW CONCLUSIONS / REPORT

• ​The hypothesis was correct because ........

• ​Should include data/reasons from the experiment that prove your hypothesis correct.

• ​Scientists then report out their findings!

• ​Their findings then undergo whats called PEER REVIEW!!!

​https://www.youtube.com/watch?v=b_tovjfQtxk