Current issue: 55(3)
Under compilation: 55(4)
There has been earlier publications on calculating the standard error of the strips. However, they have been calculated with very small amount of data. In the article the confidence of standard error will be examined throughout. The article is a response to the article written by A. Langsaeter on the theme.
The article features a critical observation on used methods for calculating the errors and a trial to improve it. The article describes the calculation method used in Sweden, county of Värmland and another method used by Ilvessalo and developed by Cajanus. The shortcomings of these models are discussed. An improved calculation is presented.