On a new method to analyse QSO spectra

A new method of analysis of QSO spectra, usually referred to as the "Thong method", has been recently presented and made use of in a number of publications. Several of these have been withdrawn because the authors have been convicted of plagiarism. However, there exists no publication showing that the method itself, which is an original contribution of the authors, is wrong. The purpose of the present note is to show that it is and that the results obtained when using it, including limits on the time variation of the fine structure constant many times smaller than published by other authors, must therefore be ignored and discarded.