You see something and wonder what is happening or how it happens. Ask a question or make a statement that you can test by an experiment. This statement is called a hypothesis. The hypothesis defines the purpose of your experiment.
Observation: My kitten plays with the yellow ball more than the dangling black feather.
Hypothesis: Kittens are more attracted to light-colored objects than darker ones.
Define the parts of your experiment that will change. These are called variables.
Variable 1: The color of the object (yellow or black).
Variable 2: The type of object (ball or feather).
Define the parts of your experiment that will not change. These are called controls.
Control 1: The kittens used as test subjects.
Control 2: Amount of time of each test.
Find out what people have already said or written about the subject. Has anyone else done an experiment to see what colors cats like most? Even so, you can still repeat their experiment or do your own to see if you get the same result.
Think of an experiment to test the hypothesis.
See whether kittens prefer yellow or black toys. See whether kittens prefer a ball or a feather. Try to find out, is it the color or the type of toy that matters most to kittens? Or do they just like to play with anything and don't care what?
Make a step-by-step list of what you are going to do. For example, you might write:
Place a yellow ball in the center of the floor and a black feather dangling on a string at kitten level.
Place a kitten in the room with the toys for 15 minutes.
Watch to see which toy the kitten plays with most.
Record the time spent with each toy.
Repeat with other kittens.
Repeat all the steps with a black ball and a yellow feather.
Now do the experiment and carefully record the data.
Figure out what the data means. Do any calculations needed or draw graphs to help you make sense of the data.
Does your data show that the kittens preferred one color over the other, or one toy over the other? You may find that the kittens liked the yellow ball and the yellow feather best. Or the black feather and the yellow feather. Or the yellow ball and the black ball. Or you may see no pattern at all, and that's OK!
Draw conclusions and write a report.
Did the data you collected support your hypothesis or not? Is there any reason to think there might be errors in your results? If the data did not support your hypothesis, what are some other hypotheses you might test to explain your initial observations? What further research could you or someone else do to verify your results?