AbstractThe residual errors obtained, after the adjustment of sequential misclosures, in four different survey processes, are analysed by the method of least squares. Values are obtained for the average error of each of the residual error distributions, on the assumption that the latter are normally distributed. The results are expressed in terms of the estimated accumulation of average error (ea) over the types of sequences considered. The samples are further subdivided according to the sequential position at which errors occur and least squares solutions effected for the average error of the normal distribution which fits the observed error distribution.