Download The Scientific Method - Petal School District

The Scientific Method:
AKA “scientific inquiry”
process used to answer questions &
gain knowledge
The 6 “Steps”
1.
2.
3.
4.
5.
6.
Question
Research
Hypothesize/Predict
Experiment/Test/Collect Data
Analyze Data & Make Data Visual
Conclude/Report results
Step 1: Question
• Comes from OBSERVATIONS
• What do you want to find out?
• Must be testable and measureable
(have a clear outcome).
• NOT opinion ex: Which flower
smells better?
Step 2: Research
•
•
•
•
prior knowledge
internet
books
ask an expert, etc.
Step 3: Hypothesis/Prediction
• an “educated guess”
• based on research from step 2!
“If, then, because” statement
• “If”: what you are planning to test
• “then”: what you expect to happen
• “because”: why you think it will happen
(justification)
Step 3: Hypothesis
Hypothesis:
Some students behave better in class if
they know there will be a reward.
Prediction:
If the school offers fun incentives,
then students will behave better
because they’ll want to receive a fun
reward.
Step 4:
Experiment/Collect Data
• must have clear procedures (steps)
• must be able to be duplicated by others
• Include a list of all materials used, AND
specific instructions.
You must:
• Do the experiment multiple times OR with
multiple items.
• Collect Data = write it ALL down
An experiment always has:
A. VARIABLES- “things” in a test that can change
3 TYPES of Variables
independent variableWhat is being tested (the IF part).
dependent variableWhat is observed/measured by the tester (the
THEN part).
constant (controlled) variable(s)Keep the same throughout ALL trials
• Ex: If I water some flowers twice as much
as other flowers, then the ones watered
more will grow taller because I know that
plants need plenty of water to grow.
Quest.: What is the independent variable?
Ans.: amount of H2O used
Quest.: What is the dependent variable?
Ans.: plant height
Quest.: What are some control variables?
Ans.: type of flowers, where planted, amount
of sunshine, soil, fertilizer, how watered
An experiment always has:
B. EXPERIMENTAL GROUP- the group or
individual in the experiment that receives the
experimental treatment.
(the “lab rats”)
An experiment might have:
Control group: the group or individual in
the experiment that is
• NOT tested
• is used as a reference for what “normal”
would be like.
• Not all experiments have
a control group
A good experiment:
•tests one “thing” at a time. Why?
•must be fair and unbiased.
• DON’T allow opinions to influence the
experiment or your results.
Step 5: Analyze the Data
• Look at your data for patterns or trends.
• Make a graph, table, diagram, etc.
Effect of sun on plant growth
7
6
What’s missing??
5
cm
4
with s un
3
without s un
2
1
0
D ay 1
D ay 2
D ay 3
D ay 4
D ay 5
D ay 6
Step 6: Conclusion
a. Valid hypothesis: hypothesis is
supported
“My hypothesis was valid because ….”
b. Invalid hypothesis: hypothesis is
NOT supported
“My hypothesis was invalid because ….”
(revise your hypothesis and try again!)
Step 6: Conclusion
A conclusion should:
• clearly answer your question
regardless if your hypothesis was
valid or invalid.
• Be supported/justified by
the data (cite the data in your
conclusion)
Read the close
up of this add
on the next
slide. You will
answer
questions about
an investigation
that uses this
product.
I wanted to test types of plant
fertilizers. I thought that using
Miracle-Gro® fertilizer makes plants
grow taller because a famous gardener
said so. I put 3 marigolds in a pot with
Miracle-Gro® and 3 marigolds in a pot
with Wal-Mart brand fertilizer.
After 8 weeks of data collection, I
found that there was no difference in
plant height but that the plants with
Miracle-Gro® have more flowers.
I wanted to test types of plant fertilizers. I
thought that using Miracle-Gro® fertilizer
makes plants grow taller because a famous
gardener said so. I put 3 marigolds in a pot
with Miracle-Gro® and 3 marigolds in a pot
with Wal-Mart brand fertilizer.
After 8 weeks of data collection, I found that
there was no difference in plant height but
that the plants with Miracle-Gro® have more
flowers.
What is your hypothesis?
Plants grown with Miracle-Gro® fertilizer will grow
taller b/c Ashley Stephenson said so.
I wanted to test types of plant fertilizers. I
thought that using Miracle-Gro® fertilizer
makes plants grow taller because a famous
gardener said so. I put 3 marigolds in a pot
with Miracle-Gro® and 3 marigolds in a pot
with Wal-Mart brand fertilizer.
After 8 weeks of data collection, I found that
there was no difference in plant height but
that the plants with Miracle-Gro® have more
flowers.
What is your prediction (If, then, b/c …)?
If plants are grown with Miracle-Gro® fertilizer, then
they will grow taller b/c Ashley Stephenson said so.
I wanted to test types of plant fertilizers. I
thought that using Miracle-Gro® fertilizer
makes plants grow taller because a famous
gardener said so. I put 3 marigolds in a pot
with Miracle-Gro® and 3 marigolds in a pot
with Wal-Mart brand fertilizer.
After 8 weeks of data collection, I found that
there was no difference in plant height but
that the plants with Miracle-Gro® have more
flowers.
What is your independent variable (IV)?
You are testing types of fertilizer.
I wanted to test types of plant fertilizers. I
thought that using Miracle-Gro® fertilizer
makes plants grow taller because a famous
gardener said so. I put 3 marigolds in a pot
with Miracle-Gro® and 3 marigolds in a pot
with Wal-Mart brand fertilizer.
After 8 weeks of data collection, I found that
there was no difference in plant height but
that the plants with Miracle-Gro® have more
flowers.
What is your dependent variable (DV)?
You are measuring plant height.
I wanted to test types of plant fertilizers. I
thought that using Miracle-Gro® fertilizer
makes plants grow taller because a famous
gardener said so. I put 3 marigolds in a pot
with Miracle-Gro® and 3 marigolds in a pot
with Wal-Mart brand fertilizer.
After 8 weeks of data collection, I found that
there was no difference in plant height but
that the plants with Miracle-Gro® have more
flowers.
What are your control variables (CV)?
Things that should all be the same include: types of
flower, amt. of H2O, amt. of sun, type of pot, etc.
I wanted to test types of plant fertilizers. I
thought that using Miracle-Gro® fertilizer
makes plants grow taller because a famous
gardener said so. I put 3 marigolds in a pot
with Miracle-Gro® and 3 marigolds in a pot
with Wal-Mart brand fertilizer.
After 8 weeks of data collection, I found that
there was no difference in plant height but
that the plants with Miracle-Gro® have more
flowers.
Is your hypothesis valid or invalid? Why?
fin
END OF Scientific Method NOTES 2014
Amber wants to see if plants grow better in
the sunlight or with indoor lighting. She put 1
Better Boy tomato plant outside in the sun
and 1 Big Tasty tomato plant inside the
house under a Gro-Light. She treated each
plant the same way during the test.
How could Amber improve this experiment?
(use for sci. method BW day 1)
3 fins