How to Write a Science Project Question

You need to understand about variables before you can write a question for your science fair project. A variable is a part of an experiment that changes, such as temperature, amount of light, size, or color. The objective of a science fair project is to have only two changing parts, Part A and Part B. Changes in Part A causes Part B to change. The names for these two parts are:

Part A: independent variable

Part B: dependent variable

You will purposely change Part A and watch for changes in Part B.

For example, in an exploratory experiment (an investigation used for research information), a salt solution is poured in a tray covered with black construction paper. After the water evaporated salt crystals were left on the paper.
Two things are happening: Water evaporated and crystals formed.
What happened first? Water evaporated.
What happened second? Crystals formed.
The water must evaporate so that the crystals can form.
The formation of crystals depends on the water evaporating.

I wonder…Would changing how fast water evaporates change the crystals that form?

What is the independent variable in the I wonder.. question? (Water evaporation from a salt solution.)

How can water evaporation be changed? (It could be slowed by decreasing the temperature and sped up by increasing the temperature.)

What is the dependent variable? (Crystal formation.)
How can crystals change? They can change in color, size, or shape.

Science Fair Project Question

The following form is a pattern to help you organize your question. You can reword your questions so that it best describes what you want to discover.

Form Question:

How does (a change in the independent variable) affect (how the dependent variable changes)?


How does the speed of water evaporation from a salt solution affect the size of salt crystals that form?