Note that the scan technology, first described by Staden [10] and employed here, is a frequentist hypothesis testing approach. A Bayesian approach presents an alternative through the use of Bayesian posterior probabilities for each site. Such an approach would require the specification of a model from which alternative sequences are drawn as well as null sequences. When a large number of observations are available the approach of Efron et al. [36] provides a compromise that yields local false discovery rates through the use of empirical Bayesian methods.