Forming Testable Questions

What is a testable question?

A testable question is one that can be

answered by designing and conducting an experiment.

Example of testable question

Will adding coffee grounds to the soil around my rose bush

make it grow taller?

This is a good testable question because it can be answered by an experiment

with results based on factual data (measurements

of the rose’s height).

Example of a not so great testable question

Do different smells cause people to

have good or bad moods?

This is not a great testable question EVEN THOUGH it could be set up as an experiment unless you set up a rating scale because it’s subjective.

How do you write a testable question?

A question that is testable should be written in the following format:

“What is the effect of _______ on ____?

Example of a Testable Question

What is the effect of wet pavement on the stopping speed of a vehicle?

How to Rewrite a Testable Question in the Correct Format

1. Read the question carefully.

What brand of shoes makes you run faster, Nike or New Balance?

How to Rewrite a Testable Question in the Correct Format

2. Determine the ‘cause’ and ‘effect’

What brand of shoes makes you run faster, Nike or New Balance?

Cause = brand of shoes you wearEffect = speed you run

How to Rewrite a Testable Question in the Correct Format

3. Plug the ‘cause’ and ‘effect’ of the question into the correct format by rewriting the question:

What is the effect of the brand of shoe you wear on the speed you can run?

Example of a Rewritten Testable Question

Will adding coffee grounds to the soil around my rose bush make it grow

taller?

Becomes

What is the effect of adding coffee grounds to the soil around my rose

bush on how tall it will grow?

What About Variables

The CAUSE is the same as the MANIPULATED VARIABLE.

What’s a manipulated variable again? It’s the thing you ‘change’ in your experiment.

It’s what you are ‘testing.’

What About Variables

• The EFFECT is the same as the RESPONDING VARIABLE.

What is a responding variable again? It’s the response you will measure from the

change you made.

Your Turn to Practice Writing Testable Questions