Before revision:  The contraction rate of this error estimate as a function of the solver's step size identifies it as a well-calibrated worst-case error . But its explicit numerical value for a certain step size , which depends on certain parameters of this class of solvers, is not automatically a good estimate of the explicit error.
After revision:  The contraction rate of this error estimate as a function of the solver's step size identifies it as a well-calibrated worst-case error , but its explicit numerical value for a certain step size , which depends on certain parameters of this class of solvers, is not automatically a good estimate of the explicit error.