TOPIC: Scientific MethodAim: Explain the steps of the Scientific

Method and describe the parts of a controlled experiment.

Do Now: TEXTBOOKS!!! Line up alphabetically. You need you ID card.

HW: Observations and Inferences reading due TUESDAY!!!

(SUPPLIES DUE MONDAY)

Let’s review…

Identify the improper lab procedure observed in the diagram.

Let’s summarize…

Identify the improper lab procedure observed in the diagram.

Describe the purpose of the Scientific Method.

• It is a way of asking questions and testing ideas about why things happen

What is the 1st step of the scientific method?

• Asking a question

• The PROBLEM

What is the 2nd step of the scientific method?

• Doing background research–By observing and by

studying books, the Internet or other sources

What is the 3rd step of the scientific method?

• Form a hypothesis

Describe what a hypothesis is.

• A possible explanation for a phenomenon, in other words, an answer to your question.

• Your educated guess

What is the 4th step of the scientific method?

• The hypothesis is tested experimentally.

What are you testing when performing an experiment?

• The hypothesis

What is the 5th step of the scientific method?

• The results of the experiment are analyzed and the scientist draws a conclusion.

Observation •Collect, organize and analyze your data

2

4

6

8

10

12

He

igh

t (c

m)

PLANTS

1 2 3 4 5 6

Growth of plants

Plant Height (cm)

1 4cm

2 5cm

3 8cm

4 2cm

5 9cm

6 11cm

Observations

What does the conclusion state?

• Did the experiment disprove the hypothesis? Did the prediction made on the basis of the hypothesis match the results of the experiment?

• Was your hypothesis right or wrong?

How does a theory differ from a hypothesis?

• A theory has a lot of experimental evidence, is broad enough to be applied to new questions and unrelated facts, and is flexible enough to be adapted to new data in the future.

1. Problem2. Hypothesis3. Experiment4. Observations5. Conclusion

Steps of the scientific method

ProblemUnder what color light will

plants grow best?

Hypothesis I think the plant under

green light will grow best because plants are green.

What is the one factor that is different between all of

these set-ups?

Experiment

1. Grow the plants for 5 weeks. 2. Each is placed under a certain color light. 3. They will get the same amount of light, &

will be watered every 2 days. 4. Their height will be measured (in

centimeters) once a week.

Conclusion My hypothesis was wrong. Plants grow

best under blue light, not green light. The plant under green light grew 11cm while the plant under green

light grew only 2 cm.

You read about Louis Pasteur’s experiment. State each part of his experiment using the parts of the scientific method on a piece of loose-leaf.

1. Problem: Louis Pasteur wondered where germs came from.

2. Background research: Louis Pasteur used a microscope to observe microscopic organisms.

3. Hypothesis: Pasteur’s hypothesis was that microscopic organisms were alive and spread under favorable conditions – and did not develop spontaneously from dead matter, as other scientists believed in his day.

4. Experiment: He used a flask of broth. If he was right, no germs would grow in a sterilized flask (one in which he had killed all the germs by boiling) but would grow in a flask that had not been sterilized. He boiled the flask until he was sure no germs were alive in it. Then he let it stand for a few days, and it remained free of germs. Then he let dust mix with the broth in the flask (he assumed that germs were on the dust), and it was cloudy and full of germs within a few days.

5. Analyze your data and draw a conclusion: Louis Pasteur concluded that heating killed germs, and that germs could travel through the air. His work resulted in the process of pasteurization, or killing germs by heating food such as milk, which has saved millions of lives by preventing disease.

•Repeat experiment

•Use a larger sample size

•Use only one variable

http://studyjams.scholastic.com/studyjams/jams/science/scientific-inquiry/scientific-methods.htm

To make results of an experiment more reliable or valid

PROBLEM

HYPOTHESIS

EXPERIMENT

OBSERVATION

CONCLUSION

People

Hate

Elephants

On

Couches

Let’s summarize…

1. List the steps of the scientific method.

2. Explain the difference between the problem and the hypothesis

3. What are you testing when performing an experiment?

4. Describe an example of an observation.

5. What are some ways to organize your data?

6. Explain what must be done to make the results more valid?

CA B

FD

E

A student wanted to determine if fertilizer X increases plant growth. She separated 10 plants into two groups. Group A received fertilizer X while Group B did not receive fertilizer X. She measured the height of each plant every other day.

Identify the following:- Variable- 2 factors that must remain constant between the set-ups

Review:

1. The first step in the scientific method is

a. to state the problem

b. Experimentation

c. to state the hypothesis

d. observation

4. When performing an experiment, you are testing the

a. problemb. hypothesisc. datad. conclusion

3. An educated guess to the problem of an experiment is known as a

a. variableb. theoryc. hypothesisd. law

5. Your senses can be used to make a(n)

a. observation b. conclusion c. hypothesis d. problem

Independent variable = ?

SUNLIGHT