For each run, a different amount of change in the variable is used. This produces a different amount of response in the system. You measure this response, or record data, in a table for this purpose. When raw data gets processed mathematically, for example, it becomes results. As you do experiments, record all numerical measurements made.
Data can be amounts of chemicals used, how long something is, the time something took, etc.
If you are not making any measurements, you probably are not doing an experimental science project. Your Observations Observations can be written descriptions of what you noticed during an experiment, or problems encountered. Keep careful notes of everything you do, and everything that happens. Observations are valuable when drawing conclusions, and useful for locating experimental errors. Perform Calculations Do any calculations needed from your raw data to obtain the numbers you need to draw your conclusions.