The science process skill used when looking at and observing the amount of garbage is observing.• Observation is the basic science skill where you use your senses (sight, smell, sometimes touch) to gather information. For example, when you notice that there are three bags of garbage or that the trash pile is getting bigger, you are using observation.If you start counting or measuring the garbage (like weighing it in kilograms or recording the number of bags), then you are also applying the skill of measuring.So the main answer is observing, but if you are quantifying it, then it’s also measuring.