Adjustment Computation, formerly known as the Theory of Errors, is an essential part of the study of Geomatics and, more recently, the qualification of civil engineers. This is partly because the mathematical modelling of physical phenomena is now very sophisticated, surveying instruments are highly automated and the results of surveying measurements are more reliable and accurate than ever before. For these reasons, Civil Engineering also requires more sophisticated data processing and statistically coherent results to assess the accuracy of measurements and to estimate confidence intervals of calculated values.