Procaryotic genes are relatively easy to find compared to Eucaryotic genes because they lack introns. By locating stop codons and then looking at the codons in the 5' direction of the stop codon, one can define an open reading frame (ORF). Many open reading frames exist in E.Coli DNA, and each is a potential gene. Determining whether a particular open reading frame is a complete gene (and consequently the location of its initiation codon) is a challenging task which can exhaust even the most patient visual searcher. It requires evaluation of multiple types of evidence which include a measure of the frequency of codon usage for the ORF, as well as an evaluation of the Shine/Delgarno site. See Fickett and Tung [5] for a review of successful gene-coding measures.