Abstract
The Information Spectrum Method (ISM) and the Resonant Recognition Model (RRM) represent a methodology based on signal processing that analyzes characteristic spectral motifs in DNA/RNA and protein sequences. Some inconsistencies have been reported recently with regard to the spectral characterization of specific biological sequences utilizing the ISM (RRM) and this motivated examination of the basics of the ISM (RRM). This note provides some discussions on the methodology on which the ISM and RRM are based and shows a potential reason why the ISM and the RRM produce inaccurate and unreliable results. Two examples are given to backup the analysis and discussion.