Infer When you infer, or make an inference, you suggest a possible expalnation for an inference, you suggest a possible explanation for an observation. You can ofter make more than one inferences to explain the same observation.
Estimate When you estimate, you make careful guesses. Estimating skills are used to gather informatioin when exact measurements are not needed or when they would be impossible or too time-consuming to get. You learn to make estimations about many things. You estimate distance, size, time, and so on.
Measure When you need exact and careful infomation about an observation, you measure. Measurements include both a number and a unit. he volume of water in a lake, the number of fish living in the lake, and the temperature at the lake’s surface – all these are forms of measurement.