Scientific Investigation
August 23, 2019
Steps of the Scientific
Investigation
•
Six Steps to the Scientific Investigation
– All scientists use the scientific investigation
•
Six Steps:
1.
2.
3.
4.
5.
6.
Problem Question
Hypothesis
Procedure/Experiment
Results/Analysis of the Data
Conclusion
Replicate/Repeat Experiment
Problem Question
1. Problem Question – what we are
trying to find out/ research
A. Must include the independent
variable and dependent variable
B. Format: How does the IV affect the
DV?
IV = independent variable
DV = dependent variable
Example: How does the mass of a toy car
affect the distance it will travel?
Hypothesis
2. Form a Hypothesis
A. Gives a solution to the problem
question
B. Tell why your solution will work
C. Model: “If, then and because”
D. Must have the independent and
dependent variables
Hypothesis, cont.
• The following format is required for writing
a hypothesis
Independent variable
(describe)
_________________
Scientific Word
(increase,
decrease)
___________
If the
is
Scientific Word
then the _______________
will __________.
Dependent variable
(inc., dec.)
(describe)
Give a personal experience, tell
I think this because____________________.
why
Example Hypothesis
If the mass of a toy car increases
then the distance the car will travel
will decrease. I think this because
when I put my two brothers and our
dog into the wheelbarrow, I could
only move them a short distance
because of their mass.
Procedure/Experiment
A. Must have all information to perform the
experiment: independent variable,
dependent variable, constants, controls,
materials, supplies
1. Remember correct format for writing a
procedure (numbered steps, command
sentences, illustration/diagram, one
instruction per step)
B. Always repeat trials to improve results –
must do 3 trials at each interval being
measured and then averaged
Results/Analysis of the Data
A. Results are presented in charts, data
tables and graphs – correct format
B. Qualitative data – requires judgment or
opinion (observations such as color
change, odor)
C. Quantitative data – data that is
measured (time, measurement of
distance, mass, temperature)
D. Must include data from the experiment
Conclusion
A. Interpret the data – was the hypothesis
supported by the data (yes or no, use
actual number data to support)
B. List any sources of error
C. List any changes you would make the
next time you conduct the experiment
Replicate/Repeat
A. Trials
Repeat the experiment over and over
again to support your findings.
Do over!
Do over!
Do over!
Hypothesis vs. Theory
• Hypothesis: An educated guess that is
tested over and over again.
• Theory: Is a hypothesis that has been
tested over and over again and proven to
be correct. Theories however can be
proven wrong and changed after additional
tests and/or observations.
Variables
1. Variables
A. Something in the experiment
that will change. Vari means to
change.
B. To make an investigation
scientific you have to have an
independent variable and a
dependent variable
Independent Variables
2. Independent Variables
A. The variable that is purposefully
changed (scientist will change)
B. Can have only ONE in an
investigation
Examples: amount of water, time,
mass, temperature
Dependent Variable
3. Dependent Variable
A. The variable that changes in response
to the independent variable (usually
measured in an investigation)
Examples: time it takes to evaporate,
bounce height of the ball, distance
traveled
Controls
4. Control for an Experiment
A. Control – the normal conditions
for the experiment that everything
will be compared back to
Constant
5. Constants/ Controlled variables
A. Things that are kept the same
throughout the entire investigation
Examples: same location, same
temperature, same conditions