The four primary sources are constitutions, statutes, cases, and regulations. These laws and rules are issued by official bodies from the three branches of government.

Measurement errors are commonly ascribed to four sources: the respondent, the interviewer, the instrument (i.e., the survey questionnaire), and the mode of data collection.

Measurement errors are commonly ascribed to four sources: the respondent, the interviewer, the instrument (i.e., the survey questionnaire), and the mode of data collection. The unique characteristics of business populations and business surveys contribute to the occurrence of specific measurement errors.

All measurements have a degree of uncertainty regardless of precision and accuracy. This is caused by two factors, the limitation of the measuring instrument (systematic error) and the skill of the experimenter making the measurements (random error).

Environmental uncertainty can be derived from several environmental components, such as customers, suppliers, competitors, distributors, regulatory factors, union issues, and technology.

Uncertainty arises from random effects and from imperfect correction for systematic effects. 5.4 Random errors arise from random variations of the observations (random effects). Every time a measurement is taken under the same conditions, random effects from various sources affect the measured value.

The accuracy of a measurement or approximation is the degree of closeness to the exact value. The error is the difference between the approximation and the exact value.

In practice, most calibration errors are some combination of zero, span, linearity, and hysteresis problems. An important point to remember is that with rare exceptions, zero errors always accompany other types of errors.