This is the second of a two part lesson on the scientific method. The earlier lesson was all about variables and this one focuses more on the procedures of the scientific method, at about the 5th and 6th grade level.
1. Download or save this slide show in order to get the PowerPoint custom animations.
Scientific
Method
Complemented by
my slideshow
Scientific Method
By Moira Whitehouse Variables
2. We introduced the variables
used in the Scientific Method in
a previous presentation. Let’s
think back about what was
covered in that presentation.
Do you remember what the
Scientific Method is?
3. The scientific method is:
1. One way scientists find out
about the world around us.
2. A method that scientists use
to answer specific questions.
4. For example:
If a cat always lands on its feet and...
when you drop your toast it always lands
butter-side down.... what happens when
you tie a piece of buttered toast to a cat’s
back.
*No cats were harmed in this thought experiment.
5. In order to understand the
Scientific Method, we first
need to know what a
VARIABLE
is.
7. Yes,
a variable is
anything in an experiment
that can change.
Remember there are three
types of variables.
What do you recall about
these three variables?
8. … a change
…a responding
variable?
…a control
variable?
variable?
14. The control variable: all the other things
that could cause the responding variable
to change—must be kept the same.
15. One more thing to remember:
The experimenter always
? ??
starts with a
? ? question ? ? ?
that can be answered by
changing a variable and
observing the results.
17. The first step in this and any
experiment is coming up with a
Problem
18. 1. Problem
• Is a question
• Is made up of
the change and
responding
variable
19. Jane knows that plants
need light to grow. But she
wonders—what about
seeds. Do seeds need light
to sprout? She decides to
design an experiment to
answer her question.
20. So in Jane’s experiment with the seeds
what will her change variable be?
Yes, it will be whether or not the
seeds receive light.
What could her responding variable
be?—what could she observe or
measure to see whether or not seeds
need light to sprout or grow?
21. She plans to put 3 seeds in light and 3
seeds in the dark and then count the
number of seeds that sprout when
light is present and the number when
light is not present.
Now that we have the change variable
(light and dark) and the responding
variable (the number of seeds that
sprout), let us write the problem—the
question with the change and
responding variable.
22. Will more seeds sprout in the light
than in the dark?
or
Does light affect the number of
seeds that sprout?
23. After you come up with a Problem, the
next step in the Scientific Method is
coming up with:
The Hypothesis.
24. 2. Hypothesis
• Answers
the question
• Predicts
what will
happen
25. What will be the hypothesis for Jane’s
experiment with light and sprouting
seeds?
What do you think? Will more seeds
sprout in the light or in the dark?
Because plants need light to grow, Jane
thinks seeds will also need light to
sprout. So her hypothesis will be:
More seeds will sprout in the light
than in the dark.
26. After coming up with an
Hypothesis, the experimenter
writes out a plan to test the
Hypothesis.
This plan is called
The Procedure
27. 3. Procedure
• Steps to be
taken to test
the hypothesis
• Includes
control
variables
28. What would be some of the control
variables in Jane’s experiment. What
besides light might affect how many seeds
sprout?
Jane thinks seeds need light to sprout. On
the next slide, you will see the step by step
plan that Jane came up with to test her
hypothesis.
Circle the change variable in red, the
responding variable in green and underline
the control variables in purple.
29. 1. Find 10 identical potting containers and
fill them with the same type of potting soil.
Place 3 pinto bean seeds in each potting
container on top of the soil-- don’t cover the
seeds with soil.
2. All ten of the pots are to be placed in the
same area, getting the same amount of
sunlight for two weeks, but:
3. Cover 5 of the pots with black paper bags
so that the seeds receive no light except
when watered.
30. 4. Each day pour 15 mL
of tap water into each
pot.
5. After two weeks count
the number of seeds that
have sprouted (started to
grow) in each pot.
32. 1. Find 10 identical potting containers and
fill them with the same type of potting soil.
Place 3 pinto bean seeds in each potting
container on top of the soil-- don’t cover the
seeds with soil.
2. All ten of the pots are to be placed in the
same area, getting the same amount of
sunlight for two weeks, but:
3. Cover 5 of the pots with black paper bags
so that the seeds can receive light only
when watered.
33. 4. Each day pour 15 mL
of tap water into each
pot.
5. After two weeks count
the number of seeds that
have sprouted (started to
grow) in each pot.
34. Once the
experimenter has
come up with a
step-by-step
procedure, he or
she gathers the
materials and
conducts the
experiment.
35. As an experimenter conducts the
experiment, he or she records the
observations or measurements
(data) in a data chart.
36.
37. To make sure that the results did
not occur due to chance, an
experimenter repeats the
experiment several times
collecting data each time.
38. Here are the results of Jane’s
experiment as shown in a data
chart.
The number of seeds that sprouted
Trial 1 Trial 2 Trial 3 Average
Light 3 seeds 3 seeds 3 seeds 3 seeds
No Light 3 seeds 3 seeds 3 seeds 3 seeds
Sometimes the results are also
shown in a graph.
39. After conducting the
experiment and gathering the
data using the steps in the
Procedure, the experimenter
4. analyzes the data
40.
41. Let us analyze Jane’s data.
The number of seeds that sprouted
Trial 1 Trial 2 Trial 3 Average
Light 3 seeds 3 seeds 3 seeds 3 seeds
No Light 3 seeds 3 seeds 3 seeds 3 seeds
We see that all seeds sprouted
in both the light and in the
dark.
42. After analyzing the data, the
experimenter comes up with a
5. Conclusion
• answers the question
allowing the experimenter to
decide if the hypothesis is right
or wrong.
43. The conclusion
• answers the
question.
•experimenter
decides if the
hypothesis is
right or wrong.
44. So what can Jane conclude?
From her data, Jane can
conclude that seeds DO
NOT need light to
sprout.
45. and ask a
question
Scientific
Method
in review