### Scientific Method and Variables.ppt

```What is mass?
2. What is weight?
3. What is the scientific method?
› After you define, list all the
parts you remember below
1.

The scientific method is a systematic way
to answer questions. It’s the process we
go through as scientists to answer
questions about the world around us!
You go through the scientific method
everyday without even thinking about it!
Observe and State the Problem
 Make a hypothesis
 Test your hypothesis through an
experiment.
 Record and analyze data.
 Draw conclusions and communicate
results.

(During this video, we will fill in the scientific
method graphic organizer)
Today, we are going to talk about the
main parts of a good experiment…
Hint: It’s not
blowing up our
classroom!

Let’s say that Brad has a pimple. He
wonders what will get rid of it. He’s
heard that putting toothpaste on the zit
will get rid of it. He’s also heard that
lemon juice will get rid of it. He decides
to rub his face with lemon juice and
toothpaste. The next morning his pimple
is gone. But which thing cured him? The
toothpaste or the lemon juice?
How many of you think it was the
 How many of you think it was the lemon
 The truth is….


THERE IS NO WAY FOR YOU TO KNOW
FOR SURE BECAUSE THIS IS A BAD
EXPERIMENT!!!
1)
2)
3)
Independent variables
Controls
Dependent variable
So What Are These?
IDENTIFYING
VARIABLES
Variable: A factor that can
change in an experiment.
Every experiment has two –
one is the cause, the other
is the effect.

Does crushing a sugar cube effect the
rate at which the sugar dissolves in the
water?
What is the cause and what is the effect?
Crushing the sugar cube is
what we predict will be the
cause.
We change this one!
This is called the
Independent Variable.
This is called the
Dependent Variable.
The time it takes to
dissolve is what we
will see the effect on.
We measure this one!

Independent Variable is the cause, the
one we will change.

Dependent Variable is the effect, the
one we will measure.
DV-
Chances of
divorce
IV- fertilizer
DV-
Plant
height
IV- weather
DV- behavior
IV-
Age
Does brushing your hair make it grow
faster?
1) Identify the independent variable.
2) Identify the dependent variable

Do car accidents increase your car
insurance cost?
1) Identify the independent variable.
2) Identify the dependent variable.

CONSTANT
A control group is a group that is not
treated. For example, if I gave some of
you raffle tickets but not everyone…who
is my control group?
 What was the control group in Tim and
Moby’s experiments?


Does fertilizer affect plant height?
› Independent Variable: fertilizer
› Dependent Variable: plant height
How can we be sure that the fertilizer is effecting
the plant height?
What would some constants be?
We must have a control to make sure that the
fertilizer is the only factor affecting plant height.
› Control: Plant that does not receive fertilizer.
Does the temperature outside effect the
chances a person will get the flu?
-IV: Temperature outside
-DV: Chances a person will get the flu
-Control: Person

What effect does a car’s speed have on
gas mileage?
1) Identify the control.

Does adding salt to water affect the
temperature at which it boils?
1) Identify the control.


20 minutes
First two with me,
 Last three with partner


Whisper!
Instant Snow! 

We will work this out together to figure
out which liquid makes the fluffiest snow!

Independent Practice
```