Why are both accuracy and reproducibility important in making a measurement?

Accuracy is how close you're measurement comes to an accepted or given value. I n many cases you do not know what the accepted value is, so you have nothing to compare your measurement with. The more often a measurement is taken with close precision, or reproducibility, the more likely you are to being close to your unknown accepted value.

There is a great short tutorial video covering accuracy and precision at Sciocity dot com