Learning Objective: SWBAT demonstrate how scientists solve problems by utilizing the steps of the scientific method

Do Now: Explain the difference between an opinion, an inference and an assumption

HW: Read pages 8-10 and 14-15. Answer questions on page 32 # 13-15 and 19-21

Thursday September 6, 2012

Learning Objective: Students Will Be Able To set up a controlled experiment

Do Now: Which of the following would be a correct hypothesis for an experiment?

1. will plants grow tall with more sunlight?

2. If plants are exposed to more sunlight,

then they will grow taller

Using the hypothesis, identify the independent variable and the dependent variable in this experiment

HW: finish lab

Friday September 7, 2011

OPINIONS

Ideas people have that may or may not be true

Opinions are often biased andshould not be included in science

INFERENCES

A conclusion or based on observations.

ASSUMPTIONSA statement that you believe to be true,

but cannot be proven. All scientists should not make assumptions.

EvidenceSupport for the idea that

something is true

How do scientists solve problems?

SCIENTIFIC METHOD!

A process that is used to logically solve problems

SCIENTIFIC METHOD

STEPS:• Problem• Observation• Research• Hypothesis• Experiment• Results/Data• Conclusion

PROBLEM• Something that needs to be solved!

• QUESTION?????

Our Problem

How does our heart rate change after exercise?

OBSERVATION

Through our 5 senses: sight, smell, taste, touch, and

sight

Our Observations

heart rate tends to increase after we exercise.

RESEARCH•The gathering of information related to your problem.

•How could we gather this research?

Our Research

LibraryScientific Journals

Internet Sources

HYPOTHESIS

• An educated guess based upon your observations

• Written as an if……. Then……. Statement

• NOT A QUESTION!!!!!!!• Must be testable

Examples of Hypotheses

If this chemical is applied to plant leaves, then the plant will grow faster.

Chemical+

If this chemical is safe, then it will not harm us when it is added to our

drinking water.

Our Hypothesis

If a person does 30 Jumping Jacks, then his/her heart rate will increase.

EXPERIMENT

A procedure to test the validity of our hypothesis

Controlled experiment Control group:

• Gets the normal treatment• Used to compare the experimental

group to

Experimental groupGets the substance or the treatment you are testing.

Our Controlled Experiment

We are going to design an experiment that will allow us to measure heart rate

after we exercise.

In our Exercise Experiment, which is the

control group and which is the experimental group?

Control no exercise

Experimental

exercise

Variables

factors that can change

Independent (manipulated) –

what the scientist controls or changes.

Our experiment: Exercise

Dependent (responding)

the variable that is observed and that changes because of the independent variable. Data (measureable)

Our experiment: Heart Rate

Constant

variables that are the same in each group.

Both groups should be treated the same except for the

independent variable

Our Experiment: Age, Exercise Type, Time of Day,

etc…)

Sample size?

The bigger the sample size, the better the results or conclusion will

be.

How many people should we use?

The number of “things” included in group.

VS

Procedure1)Half the students will measure their

heart rate for 1 minute during rest and write it on a piece of paper.

2)Half the students will be instructed to complete 30 Jumping Jacks.

3)Those students who completed the Jumping Jacks will measure their heart rate for one minute and write it on a piece of paper.

RESULTS

• Data• Written records of observations

organized in a graph or table

CONCLUSION

Explanation of the results (i.e. Why did you get those results?)

How can we increase the validity of the experiment?

1. Use a larger sample size

2. Do the experiment again

Identify the Dependent and Independent Variable:

1)In an experiment studying the effect of sleep on student achievement.

2)In an experiment studying the effect of caffeine on worker performance.

3)In an experiment studying plant growth in different colors of light.