Precision

How close repeated measurements are to each other. For example, a soil pH meter used in the field might record measurements of 6.3 to 6.5, so the degree of precision is good, with the range of measurements being narrow. If the true pH value is 5.5 then it is fair to say that the field test equipment, whilst being precise in its measurements is not very accurate, being only of general use. However, if a field piece of equipment is precise and the true value is known then a fairly simple readjustment of data can help provide much more useful information when other soils are tested. If, for example, the field test equipment is known to be consistently 0.8 ¯ 1 of a pH unit higher than the true value then only this degree of correction is needed to provide a much more accurate indication of other soils which might be tested. Compare ‘Accuracy'.