When possible, they use instruments such as microscopes and thermometers or balances to make observations. Measurements with a balance or thermometer provide numerical data that can be checked and repeated. When you make observations in science, you'll find it helpful to examine the entire object or situation first. Then, look carefully for details. Write down everything you observe.
Scientists often make inferences based on their observations.
An inference is an attempt to explain or interpret observations or to say what caused what you observed. But, it's also possible that the owner has a doctor's appointment or has taken the day off to go fishing. The only way to be sure your inference is correct is to investigate further. When making an inference, be certain to use accurate data and observations. Analyze all of the data that you've collected.