Is a measurement being made good and is it as good as the measurement that was made yesterday, a week ago, or a year ago? The question of what is good measurement is asked all the time. This paper reviews what constitutes a good measurement. In addition it discusses the means that have been established to give the individual doing the measurement confidence that it is a good measurement. First, it discusses test instrument selection. The paper looks at characteristics of a test instrument such as accuracy and repeatability. It discusses the effect of temperature on accuracy and how traceability is important to the ultimate goal of making a “good measurement.” Second, it looks at the measurement process and the factors that influence the collection of data for measurement assurance. Finally, it reviews both National and International Standards for maintaining documented traceability