2. The Scientific Method
∗What is the scientific
∗It is a process that
is used to find
the world around
3. ∗ Is there only one “scientific method”?
∗ No, there are several versions of the
∗ Some versions have more steps, while
others may have only a few.
∗ However, they all begin with the
identification of a problem or a question to
be answered based on observations of the
world around us.
4. ∗They provide an
5. ∗ What is a hypothesis?
∗ It is an educated
guess based on
your knowledge of
∗ You state it as a
possible answer to
6. ∗ Stated in the “If…..,
∗ Example: IF I water
three plants with
THEN the plant that
receives Sprite will
grow the tallest.
7. ∗What is data?
∗It is information
∗It is organized
into a data table
visually as a
∗ BAR GRAPHS: can be used to show
how something changes over time
or to compare items.
∗ have an x-axis (horizontal) and a
∗ the x-axis has time period or
what is being measured
∗ the y-axis has numbers for the
amount of stuff being measured.
∗ good when you're plotting data
that spans many years (or days,
weeks...), has really big changes
from year to year (or day to
day...), or when you are
9. ∗ LINE GRAPHS: can be used to
show how something changes
∗ x-axis has numbers for the
∗ y-axis has numbers for what is
∗ can be used when you're
plotting data that has peaks
(ups) and valleys (downs), or
that was collected in a short
∗ Used for two sets of numerical
data (ex: time and temp)
10. ∗ 1. Choose a problem: State the
problem as a question.
∗ 2. Research your problem: Read, get
advice, and make observations.
∗ 3. Develop a hypothesis: Make a
prediction about what will happen.
∗ 4. Design an experiment: Plan how you
will test your hypothesis.
Steps of the Scientific Method
11. ∗ 5. Test your hypothesis: Conduct the
experiment and record the data.
∗ 6. Organize your data: Create a chart or
graph of your data.
∗ 7. Draw conclusions: Analyze your data
and summarize your findings.
Variable – something
that is changed by
∗What is tested
3 Kinds of Variables
14. ∗Dependent Variable – something that
might be affected by the change in the
∗ What is observed
∗ What is measured
∗ The data collected during the investigation
∗ “the numbers”
∗ Example: how tall the plant grew, how far
the paper airplane flew
16. ∗Controlled Variable – a variable that is
∗Also called CONSTANTS
∗Allow for a “fair test”
∗Everything in the experiment except
for the IV should be kept constant
17. ∗ Give a detailed explanation of how you will
conduct the experiment to test your hypothesis
∗ Be clear about the variables (elements you
change) versus your constants (elements that do
∗ A control is the group that you use as a
comparison to see if change has occurred.
∗ Example: In a medicine study, the group of
people who don’t get the medicine are the
18. ∗ Be very specific about how you
will measure results to prove or
disprove your hypothesis. You
should include a regular timetable
for measuring results or
observing the projects (such as
every hour, every day, every
19. ∗ Conclusion: your results or findings based on
data collected during the experiment
∗ Answer your problem/purpose statement
∗ What does it all add up to? What is the value of
∗ What further study do you recommend given the
results of your experiment? What would be the
next question to ask?
∗ If you repeat this project, what would you
20. For Example:
Students of different ages were
given a jigsaw puzzle to put
together. The scientist wanted to
see if the students’ ages affected
how long it took to put the puzzle
21. ∗Independent Variable (IV):
∗Ages of the students
∗Different ages were tested by the scientist
∗Dependent Variable (DV):
∗The time it took to put the puzzle
∗The time was observed and measured by
Identify the Variables in this
22. ∗ (1) Same puzzle
∗ All of the participants were tested with the
∗ It would not have been a fair test if some
had an easy 30 piece puzzle and some had a
harder 500 piece puzzle.
∗ Other constants: (2) same location, (3) same
stopwatch, (4) same person timing the
What were the constants?
23. ∗ An investigation was done with an
electromagnetic system made from a battery
and wire wrapped around a nail. Different sizes
of nails were used. The number of paper clips
the electromagnet could pick up was measured.
24. ∗IV: Sizes of nails
∗These were changed by the scientist
∗DV: Number of paper clips picked up
∗The number of paper clips observed and
∗Constants: Battery, wire, type of nail
∗None of these items were changed
What are the Variables?
25. Let’s Practice!
∗If I use a heavier bowling
ball, then the ball will
travel faster down the
∗IV: weight of bowling ball
∗DV: speed it traveled
26. ∗ 2) If I use different brands of
paper towels, then Bounty
will absorb more water per
minute than Sparkle or
∗ IV: brand of paper towel
∗ DV: amount of water
absorbed per minute
27. ∗3) If I put 3 spider plants in
different locations, then the
plant in the sunlight will grow
taller in a one-week period
than the plants in the closet
∗IV: location of the plants
∗DV: height of plants