Variables What types of variables effect an experiment? How can you identify each type of variable?...

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Variables Variables

Transcript of Variables What types of variables effect an experiment? How can you identify each type of variable?...

Page 1: Variables What types of variables effect an experiment? How can you identify each type of variable? Essential questions:

VariablesVariables

Page 2: Variables What types of variables effect an experiment? How can you identify each type of variable? Essential questions:

• What types of variables effect an experiment?

• How can you identify each type of variable?

Essential questions:

Page 3: Variables What types of variables effect an experiment? How can you identify each type of variable? Essential questions:

Variables

Variables: things that change

Page 4: Variables What types of variables effect an experiment? How can you identify each type of variable? Essential questions:

Variables

In any experiment there are 3 variables:

an independent (or input) variable

a dependent (or outcome) variable

some control variables

Let’s look at each type….

Page 5: Variables What types of variables effect an experiment? How can you identify each type of variable? Essential questions:

Variables

Independent variable: The thing you decide to change.

Example 1

You decide the weight to apply, so:

Weight is the independent variable.

Investigating how a weight affects the length of an elastic band.

Page 6: Variables What types of variables effect an experiment? How can you identify each type of variable? Essential questions:

Variables

Dependent Variable: the variable that changes as a result of changing the independent variable.

This is the variable you measure

Example 1

You measure the resulting length of the elastic band, so:

Length is the dependent variable.

Investigating how a weight affects the length of an elastic band.

Page 7: Variables What types of variables effect an experiment? How can you identify each type of variable? Essential questions:

Variables

Controls: These are all the variables that must not change, to make sure it is a fair test.

Example 1

You must use the same elastic band all the time, and the same scale etc,so it is a fair test.

Investigating how a weight affects the length of an elastic band.

Page 8: Variables What types of variables effect an experiment? How can you identify each type of variable? Essential questions:
Page 9: Variables What types of variables effect an experiment? How can you identify each type of variable? Essential questions:

Variables

Example Experiment:

How does the starting temperature of a beaker of water affect the time the beaker will take to cool down?

Page 10: Variables What types of variables effect an experiment? How can you identify each type of variable? Essential questions:

Example:

Imagining this experiment, write down the : Independent variable:

Dependent variable:

Control variables

Page 11: Variables What types of variables effect an experiment? How can you identify each type of variable? Essential questions:

Example

Remember, the dependent variable is what changes as a result of your experiment, it’s the variable you measure, so…

You measure TIME, so:

Time the beaker takes to cool down is the dependent variable.

Question: How does the starting temperature of a beaker of water affect the time the beaker will take to cool down?

Page 12: Variables What types of variables effect an experiment? How can you identify each type of variable? Essential questions:

Example

Remember, the independent variable is what YOU change, so…

You change the starting temperature, so:

STARTING TEMP is the independent variable.

Question: How does the starting temperature of a beaker of water affect the time the beaker will take to cool down?

Page 13: Variables What types of variables effect an experiment? How can you identify each type of variable? Essential questions:

Example

Remember, the control variables are all the variables that must not change, to make sure it is a fair test.

You must use the same beaker, with the same amount of water, in the same position in the room, at the same room temperature,so it is a fair test.

Question: How does the starting temperature of a beaker of water affect the time the beaker will take to cool down?

Page 14: Variables What types of variables effect an experiment? How can you identify each type of variable? Essential questions:

Example:

Imagining this experiment, write down the : Independent variable:

Starting temperature

Dependent variable:

Time to cool

Control variables

Same beaker, amount of water, room temp

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Page 16: Variables What types of variables effect an experiment? How can you identify each type of variable? Essential questions:

When you draw up a table of your results,

the independent variable goes in the first column, like this:

Tables

If you take several readings of the dependent variable, then you can calculate the mean (average)Then your results will be more reliable.

Page 17: Variables What types of variables effect an experiment? How can you identify each type of variable? Essential questions:

Groups

The experimental group: the group in a scientific experiment where the experimental procedure is performed

The control group is a group that does NOT get the experimental procedure.