In this paper, we propose a method to classify prokaryotic genomes using the 
agglomerative information bottleneck method for unsupervised clustering. 
Although the method we present here is closely related to a group of methods 
based on detecting the presence or absence of genes, our method is different 
because it uses gene lengths as well. We show that this amended method is 
reliable. For robustness evaluation, we apply bootstrap and jackknife techniques 
to input data. As a result, we are able to propose an approach to determine the 
stability level of a cladogram. We demonstrate that the genome tree produced for 
a selected small group of genomes looks a lot like a phylogenetic tree of this 
group.