#### Transcript Hypothesis & Variables Powerpoint

**HYPOTHESIS AND VARIABLES**

Step 3: Form a Hypothesis **Hypothesis**- a **testable explanation **of an observation.

A hypothesis is **NOT just an educated guess** about what you think will happen. It must be able to be tested!

Step 3: Form a Hypothesis We write the hypothesis in an

**If-Then statement**

ex:

**If**

the amount of fertilizer is

**then**

the height of the plant increased, will increase.

Variables & Controls A **variable **is anything that * changes *in a scientific experiment.

The **control **is what you use to * compare *the results to in the end of the experiment.

There are 2 types of variables: Independent Dependent

Step 3: Form a Hypothesis The Independent Variable goes after the “If” I.V.

**If**

the amount of fertilizer is increased,

**then**

the height of the plant will increase.

Step 3: Form a Hypothesis The Dependent Variable goes after the “Then”

**If**

the amount of fertilizer is increased,

**then**

the height of the plant will increase. D.V.

Now You Try: If you spend more time studying, then your grade will improve.

Independent Variable = Dependent Variable =

Now You Try: If you spend more time studying, then your grade will improve.

Independent Variable = studying amount of time spent Dependent Variable = grade

Now You Try: If the temperature of the room is increased, then the bacteria will grow faster.

Independent Variable = Dependent Variable =

Now You Try: If the temperature of the room is increased, then the bacteria will grow faster.

Independent Variable = temperature of room Dependent Variable = bacterial growth

Variables & Controls A **variable **is anything that * changes *in a scientific experiment.

The **control **is what you use to * compare *the results to in the end of the experiment.

2 Types of variables: **Independent Variable**: What you change.

**Dependent Variable**: What changes because of the Independent Variable.

2 Types of variables: **Independent Variable**: Cause **Dependent Variable**: Effect

Independent Variable **Independent Variable**: What you change.

Cause a.k.a Manipulated Variable Graphed on x axis

Dependent Variable **Dependent Variable**: What changes because of the Independent Variable.

Effect a.k.a Responding Variable Graphed on y axis

Independent Variable vs. Dependent Variable

**Also Known As: Results: Independent Variable**

Manipulated Variable Cause

**Dependent Variable**

Responding Variable Effect

**On a graph:**

X axis Y axis

After all of the data from the experiment is collected, then its time to organize the data.

Step 6: Organize your data Put your data into a **data table**

**Independent Variable __________(unit) Levels Dependent Variable _______________ (unit) Trial 1 Trail 2 Trail 3 mean range**

Step 6: Organize your data Make the data table into a **graph**

**GRAPHS make it EASIER to see patterns in the data! **

Step 6: Organize your data How do you know what goes on each

**axis**

of the graph?

Step 6: Organize your data DRY MIX **D**ependent Variable = **R**esponding Variable = **Y **axis **M**anipulated Variable = **I**ndependent Variable = **X **axis

**Parts of a graph Y Axis X Axis**

**Parts of a graph Y Axis (Dependent Variable) X Axis (Independent Variable)**

Graphing: DRY MIX

**Independent Variable**

Any Questions????