2 measurement error measurement is essential for statistical processes but error is necessarily generated in measuring values absolute measurement is impossible no matter how precise a measuring instrument is 3 functional error this error is generated when the relation between an independent variable and a dependent variable is erroneously set considering these points regression model analysis tries to make an assumption on an error term in this stochastic model and to find an average relation between a dependent variable and an independent variable to complete a regression expression regression coefficients should be found however since it is not possible to find these coefficients for an entire parent group these coefficients should be estimated here a regression model of a sample can be expressed as follows and the error of the sample is called u2018 residual u2019 and expressed as e i the description will be made based on a simple regression model for convenience hence the residue e i can be obtained as follows here since a regression coefficient of a sample is used as estimation of the regression coefficient of a parent group the error of the regression expression of the parent group is large as the residue is large in addition the regression model is an expression for representing the method of expressing each measurement and includes an error term the regression expression represents a relationship between an independent variable and a dependent variable and does not include the error term there can be a few regression expressions as that regression expression the regression line that can best represent the relation between a dependent variable and an independent variable would be the line on which the sum of.