Errors Flashcards
the difference between the true value and the measured value of a quantity.
a deviation of an observation or a calculation from the true value and is often beyond the
control of the one performing the operation.
Error
inaccuracies in measurements which occur because some aspect of a surveying operation is
performed by the surveyor with carelessness, inattention, poor judgment, and improper execution.
Mistake
a large mistake.
Blunder
one which will always have the same sign and magnitude as long as field
conditions remain constant and unchanged.
Systematic error
error caused by factors beyond the control of the surveyor and are present
in all surveying measurements.
Accidental error
errors due to imperfections in the instruments used, either from faults in
their construction or from improper adjustments between the different parts prior to their use.
Instrumental error
errors caused by variations in the phenomena of nature such as changes in
magnetic declination, temperature, humidity, wind, refraction, gravity, and curvature of the earth.
Natural error
errors arising principally from limitations of the senses of sight, touch and
hearing of the human observer which are likely to be erroneous or inaccurate.
Personal error
indicates how close a given measurement is to the absolute or true value of the quantity
measured.
implies the closeness between related measurements and their expectations.
Accuracy
refers to the degree of refinement and consistency with which any physical measurement
is made.
portrayed by the closeness to one another of a set of repeated measurements of a quantity.
Precision
the number of times something will probably occur over the range of possible
occurrences.
Probability
refers to a quantity which, based on available data, has more chances of being correct than has any other.
Most probable value
sometimes referred to as deviation – defined as the difference between any measured value
of a quantity and its most probable value.
Residual
a quantity which, when added to and subtracted from the most probable value, defines a range within which there is a 50% chance that the true value of the measured quantity lies inside (or outside) the limits thus set.
Probable error
sometimes called relative precision – expressed by a fraction having the magnitude of the error in the numerator and the magnitude of the measured quantity in the denominator.
Relative error
