The difference between the true value and that which is reported from a measurement.

is any difference between the observed value and the real or true value which leads to the skewing of results if not solved.

The difference between the value measured in a survey or on a test and the ¿true¿ value, if the difference is due to factors beyond the control of the respondent. Some factors that contribute to measu [..]

The difference between a true value and an observed or reported survey value due to factors such as the survey instrument, the observer, or other elements of the data collection process.

the difference between a measured value and its true value.

Survey error (variance and bias) due to the measurement process; that is, error introduced by the survey instrument, the interviewer, or the respondent.

The difference between an observed variable and the variable that belongs in a multiple regression equation.

The error that results from the difference between the information sought and the information actually obtained by the measurement process.

The data used in an econometric problem may have been measured with some error, and if so this violates a basic condition of the abstract environment in which OLS is validly derived. This turns out no [..]

Errors in measuring an explanatory variable in a regression, which leads to biases in estimated parameters.