| 1. | the amount by which a closed traverse fails to satisfy the requirements of a true mathematical figure, as the length of line joining the true and computed position of the same point. |
| 2. | the ratio of this linear error to the perimeter of the traverse. |
| 3. | (for angles) the amount by which the sum of the observed angles fails to equal the true sum. |
| 4. | (in leveling) the amount by which an elevation determined by a series of levels fails to agree with an established elevation. |