Precision

Precision has the following meanings:

1. In engineering, science, industry and statistics, precision characterises the degree of mutual agreement among a series of individual measurements, values, or results - see accuracy and precision.
2. In computing, one of:
   1. the precision (number of digits) with which a value is expressed (e.g., the number of significant decimal digits or bits – a calculation which rounds to three digits is said to have a working precision or rounding precision of 3)
   2. the units of the least significant digit of a measurement; for example, if a measurement is 17.130 meters then its precision is millimeters (one unit in the last place, or ulp, is 1mm)
   3. (in some programming languages and databases) the number of decimal places after the decimal point in a fixed-point number; to avoid confusion, this usage is best avoided.
3. With respect to a set of independent devices of the same design, precision is the ability of these devices to produce the same value or result, given the same input conditions and operating in the same environment. (As defined by Federal Standard 1037C and MIL-STD-188.)
4. With respect to a single device, put into operation repeatedly without adjustments, precision is the ability to produce the same value or result, given the same input conditions and operating in the same environment. (As defined by Federal Standard 1037C and MIL-STD-188.)
5. In information retrieval, a measure of the number of relevant documents in the set of all documents returned by a search. It forms a natural pair with recall.
6. The Precision club bidding system in the game of contract bridge.