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Scientific Method
Ms. Yanuck’s Class
Scientific Method
• Systematic way scientists solve
problems or answer questions.
• Series of steps designed to test a
hypothesis.
Scientific Method Steps
Step 1: make observations which lead you to
ask a question or identify a problem.
Step 2: form a hypothesis about the solution
to the problem (if…then…because
statement).
Step 3: test the hypothesis with an experiment.
Step 4: data collection and organization
Step 5: make a conclusion (is your hypothesis
correct?)
Step 6: share your results
Scientific Method
Observations
Two types of Observations
1. Qualitative observations are made
using our five senses. (touch, taste, smell,
sight, hearing)
– Ex. “There is ice on the roof”
2. Quantitative observations are made
using numbers and measurement (you
can ask “how much?” or “how many?”.
– Ex. “The mass is six grams”
Observations should
be precise
• Good Observation:
“The mold was green and 5 cm long”
• Bad Observation:
“There was a lot of icky green mold”
• A hypothesis is an educated guess based
on observations that leads us to create an
experiment.
• A hypothesis is written as an
“if….then….because” statement.
• “If” explains what you, the scientist, will do.
• “Then” explains what you guess will
happen.
• “Because” explains why you think it will
happen.
Example: If Ms. Yanuck gives a test on
Friday, then the students will get a good
grade because they studied on Thursday.
• The independent variable is the thing
(condition) that the scientist controls or
changes on purpose.
The “if” part of a hypothesis.
• The dependent variable is what happens
in the experiment due to the change.
The “then” part of the hypothesis.
Experiment
• Control – part of the experiment you
do nothing to and do not change
• Constant – Everything except your
variable stays exactly the same.
• Trial – You need to test it more than
once
Data Collection and
Graphing
Data Collection and Graphs
• Data is information collected from the
experiment
• Data is used to analyze the results of an
experiment and draw a conclusion about
whether the hypothesis was proven to
be right.
• Data can be presented as graphs or
data tables.
• Examples of Graphs and Tables
Graphing
1. Title graph
2. Independent variable on the X axis
3. Dependent variable on the Y axis
4. Plot data points
5. Make a best fit line
Making Graphs
• Plot the data points
Time
(yrs.)
Height
(cm)
1 5
2 10
3 15
5 25
0 4 3 2 1
5
5
25
20
15
10
Time (years)
He
igh
t (c
m)
Conclusion
• Analyze data (find the average) and compare your results to your hypothesis.
• Graph the data to look for trends and
relationships.
• Was your hypothesis correct?
• Accept a correct hypothesis
or
Conclusion
• Reject an incorrect hypothesis. Give possible reasons for the difference between your hypothesis and the experimental results.
For a rejected hypothesis –
If you were to make another experiment
for this activity, what modification
(change) would you make to your
control?
Share Data
• Share your results with others so that they may repeat the experiment