Trueness is labeled on the vertical axis of Figure 1 , and like precision is a concept. The measure of trueness is systematic error . The idea is that a measurement is true when it is aimed squarely at the center of the target. A pipette or automated liquid handler which is true, will deliver on average a result which is close to the center. As shown in the upper left target in Figure 1 , it is possible to be true, while also having poor precision. Trueness and precision are independent of one another. Each can be increased or decreased without changing the other.