7. Selection inventions
7.1 Error margins in numerical values
The skilled person knows that numerical values relating to measurements suffer from measurement errors limiting their accuracy. For this reason, the general convention in the scientific and technical literature is applied: the last decimal place of a numerical value indicates its degree of accuracy. Where no other error margins are given, the maximum margin is ascertained by applying the rounding-off convention to the last decimal place (see T 175/97), e.g. for a measurement of 3.5 cm, the error margin is 3.45-3.54. The skilled person takes the same approach when interpreting ranges of values in patent specifications.