Your science project hypothesis is your scientific guess about what you think the results of an experiment will be when you put the question you picked to the test.
This prediction is your science project hypothesis. When creating your hypothesis keep in mind that it should incorporate the Independent Variable, and all of your Dependent Variables that you found.
For example: Our hypothesis is that a nutrient solution will outperform typical potting soil by causing a 30% increase in growth speed. The nutrient solution will outperform typical potting soil part is the Independent Variable and the 30% increase in growth speed part is the Dependent Variable.
When you think you have your perfect hypothesis, make sure that your independent and dependent variables are measurable.
If you were careful to pick a good question and avoid some of the pitfalls we mentioned then this should not be a problem. If you have to adjust your independent variable during your science fair experiment then make sure you will be able to do that.
In our tomato plant example we could adjust our experiment so that all of our plants are hydroponically grown, and some have nutrients added to the water over time and some do not. In this case we would need to ensure that we could add the nutrient during the experiment.
Make sure to note all the Controlled Variables for your science fair experiment and, well, control them! If you let one of these slip by, it could render your experiment invalid.
If find controlled variables that cant be made constant across your entire experiment, then you will need to rework your experiment to make sure it is not affected by these rogue variables.
When you come up with your hypothesis, make sure its based upon the research that you did when looking into your topic. A science project hypothesis without a basis in research is just a guess and thats not good enough for a science fair experiment.
Lastly, make sure that you can test your hypothesis in your experiment. If you are having difficulty coming up with at least an idea of how to test your hypothesis, then make it easier on yourself and rework it, or your question or both. Hey, its easy to make changes now take advantage of this before you have purchased/acquired your supplies.
Make certain you feel confident about your Question and Hypothesis before you move forward its ok to change your mind at this point but it will get more difficult to backtrack as you go forward.
Ready to continue? Then lets discuss experimentation further.