Part 3 : Types of Errors – Gross Errors

Gross errors – blunders – mistakes

Examples (Cooper, 1974):

  1. A tape reading of 38.23m may be recorded as 38.32m in the field book,
  2. The thermometer may be misread
  3. Measurement may be made between the wrong pegs

Characteristics - its magnitude is significantly very large or different in comparison to the measured values

Sources – Personal errors (careless of the observer)

Effect – Inhomogeneous observables

In practice there are variety of ways that can be employed to reduced gross errors (Mikhail, 1974)

  1. Taking multiple reading and checking for reasonable consistency
  2. Careful checking of both pointing and recording
  3. Using simple and quick technique for verification
  4. Applying logic and common sense
  5. Checking and verifying the performance of equipment, particularly those with automatic readout
  6. Repeating the experiment with perhaps slightly different technique
  7. Increasing redundancy of the observation used in a model


  1. Cooper, M.A.R. (1974). Fundamental of Survey Measurement and Analysis. Crosby Lockwood Staples, Great Britain
  2. Mikhail, E.M. (1974). Observations and Least Squares. A Dun-Donnelley Publisher, New York