When measuring a set, accuracy is the proximity of the measurements to a given value, while accuracy is the proximity of the measurements. A control diagram to analyze double-value errors is a better statistical tool because it is used to detect excessive process variability. It aims to determine whether the extent of the dispersion of errors on double values does not exceed the expected average, i.e. an average of zero and, even given the natural statistical variability of the process, a low repeatability coefficient relative to the measurement performed. The objective of this paper is to propose that, when assessing reproducibility, a means control diagram be developed when patient records are tracked at the same time, which is a common practice. A control diagram gives match limits, identifies possible outliers, facilitates the calculation of a repeatability coefficient, and displays it when there is a serial correlation. If the order in which the recordings were measured was randomized so that the researcher did not know which patient he was measuring or revalidizing, the well-known action proposed by Bland and Altman2 (1986) should be implemented. The proximity of the agreement or disagreement between these results is discussed in this paper. A measurement system may be accurate, but not accurate, but not accurate, nor accurate, or both.

If z.B. an experiment contains a systematic error, increasing the sample size generally increases accuracy, but does not improve accuracy. The result would be a consistent but imprecise chain of erroneous experience results. Eliminating systematic error improves accuracy, but does not change accuracy. The correlation coefficients presented in Table 1 are impressive, but do not mean agreement. The match is perfect only if the points are located along the regression line, i.e. a line with the Y-X equation, whereas the correlation is perfect when the dots are located along a straight line. For X-rays, the correlation coefficient is 0.9951, but the slope is significantly different from 1. Houston5 (1983) noted that there was a significant difference between X-ray measurements and that standardization was a prerequisite for better results.