Error Estimates for the Inverse Problem of Identifying Variable Coefficients by the Modified Least-squares^#

A variety of optimisation based methods have been proposed for estimating the leading coefficient in an elliptic partial differential equation. Error estimates have been proved for the equation error approach, the outpul least-squares approach, and a varintional approach. The present paper gives new error estimates for Ihe modified output least-squares and compares them with the known error estimates.