Transcript The Scientific Method

Conducting
a
Scientific Investigation
(The Scientific Method)
Step 1- Posing Questions
Ask a scientific question.
 A scientific question is one that can be
answered by gathering evidence.
 You should test only one idea, or variable.
 You should collect measurable data.
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EXAMPLE
Which freezes fasterfresh water or salt
water?
Step 2- Developing a Hypothesis
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A hypothesis is a possible explanation for a set of
observations OR an answer to a scientific question.
A hypothesis is an educated guess about how
things work.
A hypothesis is written like this: "If _____[I do this]
_____, then _____[this]_____ will happen
(BECAUSE…)" (Fill in the blanks with the
appropriate information from your own experiment.)
EXAMPLE
If salt is added to fresh
water, then the water
will take longer to
freeze. (because…)
Step 3- Designing an Experiment
You will need to plan HOW you will test
your hypothesis. You must decide on…
A step-by-step procedure
 The materials needed
 How the data will be recorded
 How the data will be measured
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You will also need to consider…
How to Control Variables
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You need to keep all variables the same except
for one.
Variable- any factor that can change in an
experiment.
Manipulated Variable- the factor that has been
changed in an experiment (you have changed it) –
AKA Independent Variable
Responding Variable- what you measure to
observe or obtain your results. –AKA Dependent
Variable
Controlled Experiment- an experiment in which
all factors except one are kept constant
How to Form an Operational
Definition
An operational definition is a statement
that describes how a particular variable is
to be measured or how a term is to be
defined.
EXAMPLE
What does it mean to be frozen?
Your operational definition for frozen may
putting a stick into each container, and
when the stick no longer moves, the liquid
has frozen.
Step 4- Interpreting Data
After you collect your data, you need to
organize it in a table or graph
 ANALYZE!! You need to look for patterns
or trends, then decide what the data
revealed.
 Does it
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Support you hypothesis?
 Point out flaws in your experiment?
 Tell you to collect more data?
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Step 5- Drawing Conclusions
A conclusion is a statement that sums up
what you have learned from the
experiment.