Observational errors:

Observational errors are introduced since of involvement of human factor within surveying process. It should be accepted which whenever a human element is included, the process result will be influenced through the attitude, efficiency and perception of individual human being in a subjective manner. These could be prevented through proper training of surveyors, prescribing adequate and appropriate precautions to be undertaken in every observational and measurement process, and specifying proper and detailed method statements for performing each operation of the process.

Both these categories of errors, i.e. instrumental and observational, could be further classified into:

(a) Gross errors,

(b) Systematic errors, and

(c) Accidental or random errors.