Final answer:
The statement is true. Measurements in science are indeed a way to quantitatively express and reduce uncertainty about physical quantities through observation and experimentation.
Step-by-step explanation:
The statement that measurement can also be defined as a quantitatively expressed reduction of uncertainty based on one or more observations is indeed true. When we perform measurements in scientific experiments, they provide us with essential data about the size, magnitude, and units of the phenomena under study, but also about the uncertainty inherent in these measurements. This uncertainty arises from the limitations of our measuring tools and the inherent variability in the measurements we make. It is quantitatively expressed through significant figures, margins of error, or confidence intervals.
For example, if a paper is measured to be 11 inches long with a possible uncertainty of ±0.2 inches, it communicates that the true length could reasonably be between 10.8 and 11.2 inches. In this way, measurement is a tool to reduce uncertainty about the true value of the measured entity through careful observation and quantification.
Counting, as an exception, provides exact numbers and no uncertainty, as long as the counted objects remain unchanged during counting. Thus, each measurement, beyond counting, is an estimate with a degree of uncertainty that must be accounted for in scientific analysis.