It is well known that unstability of solutions to small changes in inputs causes many problems in numerical computations. Existence, uniqueness and stability of solutions are important features of mathematical problems. Problems that fail to satisfy these conditions are called imposed. The purpose of this study is to remind briefly some methods of solution to ill-posed problems and to see the impacts or connections of these techniques to some statistical methods. (C) 2000 Elsevier Science Inc. All rights reserved. AMS classification: 65F35; 62J07.