Scientific Method
An orderly and systematic manner
scientist use to solve a problem.
INB, Pages 39 - 40
What is the scientific method?

It is a simple method scientists use to
conduct an investigation.

It is a way to ask & answer scientific
questions by conducting experiments.
Scientific Method - Steps
Ask a Question/State the Problem
 Gathering Information on the Problem
(Background)
 Forming a Hypothesis
 Performing Experiments to Test the
Hypothesis
 Recording and Analyzing Data
 Stating a Conclusion

Question/Problem - before investigating any
problem, a scientist must develop a clear
statement defining the problem

Ask a question about something
observed.
– Why?
– How?
– What?
Question to be solved.
 Must be about something measurable.

Variables

Variables are factors, conditions and/or
relationships that can change or be
changed in an event or system.
Independent Variable

The independent variable is the variable you
purposely change.
 Example:
– A student has failed his last 2 tests. What could
he change to get a better grade on the next test?
– Whatever he changes would be the independent
variable.
• Study more
• Take better notes
• Make note cards
Dependent Variable
The dependent variable is the variable
that is being observed, which changes
in response to the independent variable.
 Example:

– The grade on the next test would be the
dependent variable. It’s changing in
response to:
• Studying more
• Taking better notes etc.
Controlled Variables
(The variables that are not changed are
called controlled variables.
 Example:

– The teacher
– The time of day the student is in class
– The other students in the class
Practice: Identify 4 variables
in the following situations

What variables can affect attendance
at a football game?

What variables can affect the
number of eggs laid by a chicken?

What variables can affect the taste of
a soft drink?
More Practice

What variables can affect the
amount of fruit produced by an
apple tree?

What variables can affect the speed
of a runner in a 100-yard dash?
Hypothesis

Educated guess about how things work.
– gives a logical explanation that can be
tested.
– give an exact focus for an experiment

Use If, then statements
– If ____ [I do this – Independent Variable],
then_____[this will happen – Dependent
Variable]
Hypothesis Practice
Statement of the Problem:
 To what extent does the length of
daylight affect chicken egg production?


For the statement of the problem above,
which is the dependent variable and
which is the independent variable?
(You may use the definitions in your lab
book if you need help!)
Hypothesis example continued
Independent Variable = length of daylight
Dependent Variable = egg production
More Practice
Using this information, write a sample
hypothesis for this statement of the
problem:
To what extent does the length of
daylight affect chicken egg production?
Check Your Answer!
 Hypothesis
- If the length of
daylight increases, then
chicken egg production will
increase.
Experiment
 Tests
your hypothesis.
Is it accepted (right) or rejected
(wrong)?
 Change only one variable at a time.
 Use a control or control group (A group

that has nothing done to it. Standard used for
comparison in an experiment.)

In order for results to be valid, conduct
several tests.
Organizing Data

Organizing Data helps you interpret
what has been observed.
Data Analysis
Data interpretation = making sense of
observations
 Data tables and charts are used to
organize information
 Graphs are created from data tables for
a visual image of the observations
 Valid conclusions depend on good
organization and clear interpretation of
data

Making a Data Table
Divide the table into sections for each
piece of data
 Independent variable goes on the left
 Dependent variable goes on the right

A seed was planted. As the plant grew, it was
measured over a six day period. IV = days and
the DV = growth
Independent Variable
Dependent Variable
Day one
O cm
Day two
2 cm
Day three
5 cm
Day four
7 cm
Day five
8 cm
Day six
10 cm
Data Table Practice: Make a data table for each
of the investigations below (make sure that your
title is correct for your data table).
1. Tomato plants were grown at various temperatures. The number
of tomatoes that grew on each plant was counted
IV –
DV Data: 8⁰C – 4 tomatoes; 12 ⁰ C – 10 tomatoes; 16 ⁰ C - 14
tomatoes; 18 ⁰ C – 18 tomatoes; 22 ⁰ C – 24 tomatoes; 24 ⁰ C –
16 tomatoes
2. Different types of balls were bounced from a table top. The
height of each bounce was measured.
IV –
DV Data: golf ball – 54 cm; baseball – 9 cm; tennis ball – 48 cm;
ping pong ball – 21 cm; Styrofoam ball – 3 cm
Graphing- Make a graph for each of the
investigations below (make sure that the title of
your graph is correct).
1. Tomato plants were grown at various temperatures. The number
of tomatoes that grew on each plant was counted
IV –
DV Data: 8⁰C – 4 tomatoes; 12 ⁰ C – 10 tomatoes; 16 ⁰ C - 14
tomatoes; 18 ⁰ C – 18 tomatoes; 22 ⁰ C – 24 tomatoes; 24 ⁰ C –
16 tomatoes
2. Different types of balls were bounced from a table top. The
height of each bounce was measured.
IV –
DV Data: golf ball – 54 cm; baseball – 9 cm; tennis ball – 48 cm; ping
pong ball – 21 cm; Styrofoam ball – 3 cm
More Graphing Practice
3. Students in a science class were asked what type of pet they have. The
number of each type of pet was recorded.
IV –
DV –
Data: Cats – 7; dogs – 6; hamsters – 3; hermit crabs – 2; snakes – 1
4. The types an d numbers of cars in the teacher’s parking lot were recorded.
IV –
DV Data: Ford – 12; Chevy – 16; Dodge – 9; Volvo – 1; Honda – 2; Toyota – 1
5. A student investigated and recorded how the amount of study time
affected the scores on a science test.
IV –
DV –
Data: 0 hours – 58 points; 1 hour – 66 points; 2 hours – 82 points; 3 hours
– 84 points; 4 hours – 88 points; 5 hours – 90 points; 6 hours – 88 points
Conclusion

Summary of your experiment.
 After your experiment, analyze your data to
see if your hypothesis was accepted or
rejected.
 If hypothesis is rejected, give possible
reasons for the difference between your
hypothesis and the experimental
results.
Scientific Theory……
Scientific Law vs. Scientific
Theory
Scientific Law
Scientific Theory
When a scientific
theory has been
tested many times
and is generally
accepted as true.
Example: law of
gravity
The most logical
explanation for
events that happen
in nature.
Example: Black Hole
Theory
Layered Look Book Foldable
1. Stack five sheets of
paper together, placing each
consecutive sheet around an
inch higher than the sheet in
front of it.
2. Bring the bottom of
both sheets upwards and
align the edges so that all
of the layers
are one inch apart.
3. When all of the tabs are equal distance apart, fold the
papers and crease well. Cut down the middle of the layered
book and share with a partner.

Add the following headings to each
layer of your foldable:
– The Scientific Method
– Ask a Question
– Research
– Form Hypothesis
– Design Experiment
– Gather and Analyze Data
– Conclusion
– Types of Variables
– Scientific Theory vs. Scientific Law
What to do with the Layered Book?

Staple the Layered Booked in your INB
on page 41

Use each tab in the layered book to
help organize your notes on the steps of
the scientific method
Foldable

Use your notes and the lab rubric (p. 16
in your INB) to complete the foldable!
Make sure that each section of the
foldable has a detailed definition of each
step of the scientific method.
Share Results
Further Research
• Research on your • Research more about
the scientific method.
own about where a
• Find the names of
scientist might
which scientists
share scientific
helped contribute to
results.
the modern day
• Find at least 3
scientific method
• Find at least 3
sources were
interesting facts that
scientific results
were not talked about
are shared
in our notes.