THE SCIENTIFIC METHOD

Explain the steps in the scientific method.

STEP 1 Ask a Question based on your observations: How, what, why, where, when or who?

In order to use the scientific method to answer the question, it must be about something that you can measure, preferably with a number

STEP 2

Conduct background research –

Doing so will provide you with valuable information and help you choose the best way to conduct your experiment

STEP 3 Construct a hypothesis – an educated

guess about the question you are trying to answer.

State your hypothesis as an “If . . . . . , then. . .” statement.

You must state your hypothesis in a way that you can easily measure.

Construct your hypothesis so it will help you answer your original question.

STEP 4 Test your hypothesis with an

experiment. Your experiment tests whether your

hypothesis is true or false. Be sure that you are testing only one

factor at a time while keeping all other conditions constant

CONTROLLED EXPERIMENT A variable is something that can be changed in the experiment.  Everything else must be the same. Only one variable or condition is changed.

EXAMPLE A good problem question for a

controlled experiment can usually be phrased in this form:

How does one thing (manipulated variable) affect another thing (responding variable)?

Ex. “How does the temperature of water affect the ability of sugar to dissolve?”

VARIABLES Manipulated Variables – the variable that is changed and controlled by the scientist.

Responding Variables – the variable that is observed and that changes in response to the manipulated variable.

NOTE ABOUT VARIABLES: MANIPULATED VARIABLE IS THE SAME THING AS THE INDEPENDENT VARIABLE;

RESPONDING VARIABLE IS THE SAME THING AS THE DEPENDENT VARIABLE;

OTHER PARTS OF A CONTROLLED EXPERIMENT A control group should be used when conducting an experiment.  This group is not tested. It is the standard for comparison.

OTHER PARTS OF A CONTROLLED EXPERIMENT Constant – factors in an experiment that remain the same.

Why? No change so there is no influence on the outcome of the experiment.

EXAMPLE OF CONTROLLED EXPERIMENT QUESTION:  How will the amount of fertilizer used  affect plant growth?

HYPOTHESIS:  If the amounts of fertilizer are increased, then there will be greater growth in tomato plants.

TEST VARIABLE:  The amount of fertilizer used.  

EXAMPLE, CONTINUED

TEST CONSTANTS: The seeds must all come from the same package. All seeds must be planted in the same sized pots

with similar soil. All plants must receive exactly the same amount

of water and light. The temperature should be the same for all test

plants.

 

CONTROL GROUP Set one group as the CONTROL GROUP.  This

group is not given fertilizer. Set up two other test groups.  Once receives a

certain amount of fertilizer and the other receives twice as much.

 

EXAMPLE, CONTINUED ANALYSIS OF DATA:  A triple bar graph

or line graph of the growth of your plants. CONCLUSION:  Which plant group grew the most?  Why or why not?  What would you do differently next time?    

BACK TO THE SCIENTIFIC METHOD Step 5: Collect/record data from your experiment

Step 6: Draw a conclusion – analyze your results to see if your hypothesis is true or false.

IN THE REAL WORLD

Repeated experimentation leads to the formation of a:

Theory – a well-tested explanation that unifies a broad range of observations

LAB REPORT TEMPLATE Lab Report Template Title: * a brief, concise, yet descriptive title Statement of the Problem: * What question(s) are you trying to answer?

* Include any preliminary observations or background information about the subject

Hypothesis: * Write a possible solution for the problem.

* Make sure this possible solution is a complete sentence.* Make sure the statement is testable.

LAB REPORT TEMPLATE Materials: * Make a list of ALL items used in the lab. Procedure: * Write a paragraph (complete sentences) which

explains what you did in the lab. * Your procedure should be written so that anyone else could repeat the experiment.

Results (Data): * This section should include any data tables,

observations, or additional notes you make during the lab. * You may attach a separate sheet(s) if necessary.* All tables, graphs and charts should be labeled appropriately

LAB REPORT TEMPLATE Conclusions: * Accept or reject your hypothesis.

* EXPLAIN why you accepted or rejected your hypothesis using data from the lab.* Include a summary of the data - averages, highest, lowest..etc to help the reader understand your results* List one thing you learned and describe how it applies to a real-life situation. *Discuss possible errors that could have occurred in the collection of the data (experimental errors)