Using the Scientific Method

Scientific MethodWhat is the scientific method?

Scientists use certain methods to seek answers and solutions to problems in nature.

Scientific Method:

Is a special way in which scientists gather information and test ideas.

Is a logical way of solving problems.

STEPS OF THE SCIENTIFIC METHOD

1. State (define) the problem; Ask a question

2. Get background information; Do research

3. Form a hypothesis

4. Test the hypothesis (long process)

5. Record and analyze the data/results

6. Draw a conclusion & Communicate Results

1. STATE THE PROBLEM State the problem clearly

State only one problem at a time.

Problem statement is in a form of a question.

Examples:• “ Why won’t my lawn mower start?”• “ Why won’t my pen write?”• “Why won’t my roses flower?”

2. Get background information

Use the library - ask people about the problem

Ask an expert

Find out the factors that causes roses to flower.• Water.• Sunlight• Temperature• Condition of the soil• Air ( O2 or CO2 )

3. FORM A HYPOTHESISHypothesis:

Is a proposed answer to a question

The best guess or an educated guess.

It ALWAYS includes:– What you’re testing– A prediction about the results– Reasoning for your prediction

Anybody should be able to set up an experiment based only on your hypothesis.

Hypotheses look like…

If (what you’re going to do),

then (predict the result),

because (reason for prediction).

4. TEST THE HYPOTHESISExperiments are done in TWO Parts or Groups

Experimental Group: -- Deals with the factor or conditions that is being tested .

Control Group: -- Deals with the factor or condition that is used to compare.

Procedure:

Describes how you are going to do the experiment.

Longest part of the experiment and explains in detail how you are going to do the experiment so that other scientist can duplicate the experiment.

Variable Factor in a group that is different from

another group.

Note: - During an experiment only One variable is tested at a time so that the results are not confusing.

Types of variables.Controlled Variables: (things to keep the same) List

all the things you will not change during the experiment.

Independent Variable: (the one thing that changes) List the one thing you are changing during the experiment. Change only one thing at a time.

Also called the Manipulated Variable

Dependent variable: (the thing you are measuring). List the things you are measuring and give the units you will use.

Also called the Responding Variable

5. RECORD AND ANALYZE DATAObservation: Use our senses( smell, sight, touch, hear, taste)

DATA

Qualitative data: -- Observation that has been made without the use of instrument, does not have a number and is not accurate. ( it’s hot in this room)

Quantitative data: -- Observation that has been made with the use of an instrument, has numbers and is accurate.( It is 700 F ).

Note: Data may be presented in the following ways:

Paragraphs

Charts

Graphs

Data tables

Diagrams

Pictures

6. CONCLUSION Is a statement that states whether or not

the hypothesis that had been stated is true (correct) or not.

If the data of the experiment does not support the hypothesis, then the hypothesis needs to be changed or reworded to support the data.

Do not change the data to support the hypothesis.

Example Time: Monster Energy

Say you wanted to test the effects of drinking too much Monster on humans.

– You give every test subject 10 cans of Monster and everybody feels very sick.

– How can you prove this is due to the Monster?

Monster Energy Tips

Use a Control! – Group or object in an experiment that is NOT given “treatment”.

– In this case, a group of people in the experiment are not given Monster.

– They get EVERYTHING ELSE that the experimental group did, just no Monster.

– They are the CONTROL group.

Monster Energy Tips

Everything that changes about the groups in the experiment is a VARIABLE.

– This includes:The number of Monsters they drank

– Independent Variable (Manipulated)

The effects felt by the people in the groups– Dependent Variable (Responding)

Monster Energy Tips

Try to eliminate as many variables as possible. The only variables in the experiment should be:

– What you are testing (Monster/ no Monster)Independent Variable/ Manipulated Variable

– What you are measuring (effects of Monster)Dependent Variable/ Responding Variable

Monster Energy Tips

A HYPOTHESIS is…

Your educated guess as to what will happen when you test something.

It always includes:– What you’re testing– A prediction about the results– Reasoning for your prediction

Anybody should be able to set up an experiment based only on your hypothesis.

Monster Energy Tips

Remember a Hypothesis looks like…..

If (what you’re going to do),

then (predict the result),

because (reason for prediction).

For the Monster experiment…

Give a hypothesis using the formula

If (what you’re going to do),

then (predict the result),

because (reason for prediction).

Let’s Practice!!!

Directions:

Figure out how you would test the following problems. Write down the variables and a control group for each one, and list them in your science notebook. Then, write a practice hypothesis for that test.

Problem:1. Independent Variable (changing):• Look for the word “does.” What follows this word in the independent variable.

Dependent Variable (measuring):• Look for words like “causes, affects.” What follows this word in the dependent variable.

2. Controlled (Constant) Variables:

3. Control Group (does not get the treatment):

4. Hypothesis: If [what you’re testing] (independent variable), then [predict the result] (dependent variable), because [reason for prediction].

Problem: Does salt in soil affect plant growth?

1. Variables you will allow (what you are testing, what you are measuring):

2. Variables you need to eliminate:

3. Control Group:

4. Hypothesis: If [what you’re testing], then [predict the result], because [reason for prediction].

Problem: Does temperature cause tree leaves to change color?

1. Variables you will allow (what you are testing, what you are measuring):

2. Variables you need to eliminate:

3. Control Group:

4. Hypothesis: If [what you’re testing], then [predict the result], because [reason for prediction].

Problem: Is bacterial growth affected by temperature?

1. Variables you will allow (what you are testing, what you are measuring):

2. Variables you need to eliminate:

3. Control Group:

4. Hypothesis: If [what you’re testing], then [predict the result], because [reason for prediction].

Problem: Is plant growth affected by the color of light?

1. Variables you will allow (what you are testing, what you are measuring):

2. Variables you need to eliminate:

3. Control Group:

4. Hypothesis: If [what you’re testing], then [predict the result], because [reason for prediction].

More Practice

Directions: Open up to the next available page in your science

notebook. Title this activity “The Simpsons Controls and

Variables”• Don’t forget to write this in your table of contents

Write down the number and the answer to the question.

The Simpsons Controls and Variables

Smithers thinks that a special juice will increase the productivity of workers. He creates two groups of 50 workers each and assigns each group the same task (in this case, they're supposed to staple a set of papers). Group A is given the special juice to drink while they work. Group B is not given the special juice. After an hour, Smithers counts how many stacks of papers each group has made. Group A made 1,587 stacks, Group B made 2,113 stacks.

Identify the:1. Control Group2. Independent Variable3. Dependent Variable4. What should Smithers' conclusion be?5. How could this experiment be improved?

The Simpsons Controls and Variables

Homer notices that his shower is covered in a strange green slime. His friend Barney tells him that coconut juice will get rid of the green slime. Homer decides to check this this out by spraying half of the shower with coconut juice. He sprays the other half of the shower with water. After 3 days of "treatment" there is no change in the appearance of the green slime on either side of the shower.

6. What was the initial observation?Identify the:7. Control Group8. Independent Variable9. Dependent Variable10. What should Homer's conclusion be?

The Simpsons Controls and Variables

Bart believes that mice exposed to radiowaves will become extra strong (maybe he's been reading too much Radioactive Man). He decides to perform this experiment by placing 10 mice near a radio for 5 hours. He compared these 10 mice to another 10 mice that had not been exposed. His test consisted of a heavy block of wood that blocked the mouse food. he found that 8 out of 10 of the radiowaved mice were able to push the block away. 7 out of 10 of the other mice were able to do the same.

Identify the:11. Control Group12. Independent Variable13. Dependent Variable14. What should Bart's conclusion be?15. How could Bart's experiment be improved?

The Simpsons Controls and Variables

Krusty was told that a certain itching powder was the newest best thing on the market, it even claims to cause 50% longer lasting itches. Interested in this product, he buys the itching powder and compares it to his usual product. One test subject (A) is sprinkled with the original itching powder, and another test subject (B) was sprinkled with the Experimental itching powder. Subject A reported having itches for 30 minutes. Subject B reported to have itches for 45 minutes

Identify the:16. Control Group17. Independent Variable18. Dependent Variable19. Explain whether the data supports the advertisements claims about its product.