# 3.2: Introduction


A principle objective of science is to describe the physical world through measurement.  While we often begin with a hypothesis in science, it is important to make precise measurements and to determine the accuracy of these measurements.  There is always some amount of error, so measurements should be made several times; the average of several measurements will lessen the amount of error introduced by the measuring process.  The words precision and accuracy are often used interchangeably in common language, however, these two words have very different meanings.