Description: This paper considers the different approaches of measurement and their accuracy. Through comparative analysis of the approaches their compatibility and fields of application are evaluated. The analysis of the considered approaches is shown by the presence of evolution in philosophy of measuring. All approaches use the same mathematical vehicle. There is not distinction in understanding of probabilistic character of measuring. A measuring result is examined as approaching, estimation of size of the measured size – as an estimation, having the accuracy descriptions.
Keywords: measuring, approach, estimation, error, measuring vagueness