1. Hypothesis The definitive guide on how to write a hypothesis
Northwest Middle School
H. Morgan

2. What is a hypothesis?
A hypothesis is an educated guess or prediction about how things work.
A hypothesis is testable; an experimental investigation can be done based on the hypothesis.
Not every question can be answered by the scientific method. The hypothesis is the key. If you can state your question as a testable hypothesis, then you can use the scientific method to obtain an answer, which means you can do it as a science fair project.

3. Identify your variables
What is your independent variable?
What are you changing?
It should be only one thing.
What is your dependent variable?
What are you measuring?

4. Hypothesis Format Use an “If…, Then….” statement.
An If, Then statement shows cause and effect.
In other words, what effect does the independent variable have on the dependent variable? Or what does the independent variable cause the dependent variable to do?
Write a research hypothesis using this format:
IF the independent variable changes, THEN the dependent variable will change.
Use the words
AFFECT – verb – to act upon, to change or to cause a change
EFFECT – noun – result; consequence
When you affect something, you produce an effect on it.

5. Let’s Practice On a separate piece of paper, write your name.
On the top line, create a title for your science fair topic.
Identify the independent variable
Identify the dependent variable
Now we are ready to write our hypothesis.
If (I change this, independent variable), then (this will happen, dependent variable.)