Aim: What are the steps of the scientific
method?
Do Now:
1. What is the scientific method?
2. List the steps of the scientific method.
Homework: Handout
(Read pgs 3-5 & answer ques. (1-7)
What is the
scientific
method?
An organized set of
investigation procedures that
include:
1.
2.
3.
4.
5.
6.
State the problem
Research & Gather Info.
Form Hypothesis
Test Hypothesis (Experiment)
Record & Analyze Data
Draw Conclusion
1. State the Problem
develop a question you want to answer
2. Research
find out what is already known about your
subject, & make your own observations
3. Form a Hypothesis
• an educated guess or possible answer to your
question that is based on your research
• This may or may not be correct
• Start with “I think…, I predict…, or
If…then…”
4. Experiment
an organized process used to test your
hypothesis
5. Record and Analyze Data
• Use your 5 senses in order to make observations
• Use various tools in order to improve or extend your
power of observation
• Inferences (logical explanations) about data can be made
• use data tables to keep
track of measurements &
graphs to identify trends in
the data
•Cyclic Events (repeat over
& over) can be used to make
predictions about the future
6. Conclusion
•a judgment based on the results of an experiment
•explains what the data means
Does data support hypothesis?
If answer is NO If answer is YES
Form a new
hypothesis &
conduct a different
experiment
Repeat the
experiment several
times
Why repeat a) It is only considered to be
the
valid if you get the same
experiment
results each & every time
several times?
you repeat the experiment
b) Publish your exp. so that
other scientists can check
your results & progress
can be made in science
What is the difference between
a Theory & a Scientific Law?
Theory
• a former hypothesis that has been supported by
many experiments
• can still be changed or discarded
Scientific Law
• a statement about what happens in nature that
can’t be explained
• seems to happen in the same way all the time
• ex: the law of gravity, Newton’s Laws of Motion
Aim: How can we set up a controlled
experiment?
Do Now:
1. Take out homework handout.
2. Complete questions on the back of page 7 on
the Scientific Method
Homework: Handout (section 1-2 pgs 15 & 16)
Controlled Experiments
1. Set up two or more groups for comparison
(Control group & Experimental group(s))
2. Groups are set up to be alike in all ways except one
3. The one difference between the two groups at the start
of the experiment is called the “independent variable”
4. Experimental Group(s) is (are) exposed to the
independent variable, the Control Group is not
5. Significant differences in results are probably caused
by the independent variable
What is the difference
between the independent
& dependent variable?
1. Independent Variable
•
•
•
•
The one part of the experiment that you change
The one thing being tested
Should cause a response to occur.
Always on the X-axis of a graph
2. Dependent Variable
• a.k.a. the responding variable, or the factor being
affected or changed in response to the independent
variable
• Always on the Y-axis of a graph
Y-axis
Dependent Variable
Growth (cm)
Time (Days)
Independent Variable
X-axis
What is the
control group?
• It doesn’t contain the
independent variable
• Used for comparison
What is the
experimental
group?
• It contains the
independent variable
• (the one factor in the
experiment that is
tested)
Which experiment shows the control set-up
& which shows the experimental set-up?
Why should we
only have one
independent
variable in an
experiment?
If there were more than
one independent variable,
you wouldn’t know which
variable caused the
experimental result.
What are characteristics
of good experiments?
1. Use large numbers in each group
a) this increases the reliability of your results
because it decreases the chances of random error
occurring
b) Example: In an exp. using seeds, maybe some
were not going to germinate because a genetic
flaw, or some were affected by a bacteria or
fungus…
c) Random error with a small sample size can lead
to false conclusions!!!
2. Validity
 Data may be altered when financial gain is
on the line.
 To check this, other scientists should be
able to get similar results if they repeat your
procedures
3. Cautious Conclusions
• don’t overstate the meaning of your data
• results could be affected by factors that you are
unaware of
Aim: Lab: What do you know about the
Scientific Method?
(Sponge Bob Experiments)
Do Now:
1. Take out homework handout.
2. What is the difference between the independent
& dependent variables in an experiment?
3. What is the purpose of a control group?
Homework: Complete Lab
Aim: 1. Take Quiz
2. What is the difference between an
observation & an inference?
Do Now:
1. Prepare for Quiz
2. Make a list of observations that you notice
about this classroom.
Homework: Have a Great Weekend!!!
Quiz: Scientific Method
1. The_______________ Group is exposed to the
independent variable.
2. The Control Group in the experiment is used
for ______________.
3. The responding variable is also known as the
________________ variable.
4. The ___________ variable is always located on
the X-axis of a graph.
5. An educated guess or possible answer to your
question that is based on your research is
known as ________________.
Quiz: Scientific Method
6. When stating the problem you must develop a
_______________ you want to answer.
• The last step in the Scientific Method is to state
__________________.
8. A ___________ is a former hypothesis that has been
supported by many experiments and can still be
changed or discarded.
9. Use _______ _________ in each group to increase the
reliability of your results because it decreases the
chances of random error occurring.
Bonus: The parts of an experiment that stay the same are
known as ________________.