what it the purpose of data in a science project?

Answer 1

Data is very important to any scientific experiment. People examining your experiment later should be able to follow your process and get the same data you did. Also, you can use the data to see how precise your experiment was. Were all of your results close together, or were they scattered about. Also, you will use the data in your experiment to come up with a final conclusion for your science project. Technically without data, a experiment/science project would not exist.

Answer 2

The purpose of data in a science project, or in any experiment, is to show that SOMETHING HAPPENS. Something that would not happen in a "control group" (meaning a sample in which you have changed nothing--you have just let nature run its course), but happens in your experiment, is considered "significant."
For instance, let's say that you want to grow orchids for your science project. You should know that orchids have seeds the size of pollen grains, and they cannot grow in just a pot of dirt. They must be grown in a sterile medium. You have to take a solution of agar (a gelatin-like substance), charcoal, and nutrients, and put this in petri dishes. Then you put the orchid seeds on the medium and see what happens.
But at the same time, you take the orchid seeds and put them in a pot of dirt, and also see what happens.
After a few days, you will see that the sterile medium has tiny orchid plants sprouting from it, while your "control group" (the pot of dirt), has nothing but fungus.
Let us say that you performed this experiment 100 times.
Therefore, by your data, you have shown that in your particular geographical location, it is likely that orchids cannot sprout unless they are grown in a sterile medium.
This is the importance of data in a science project.