  This paper presents our preprocessing and clustering analysis on the
clickstream dataset proposed for the ECMLPKDD 2005 Discovery Challenge. The
main contributions of this article are double. First, after presenting the
clickstream dataset, we show how we build a rich data warehouse based an
advanced preprocesing. We take into account the intersite aspects in the given
ecommerce domain, which offers an interesting data structuration. A preliminary
statistical analysis based on time period clickstreams is given, emphasing the
importance of intersite user visits in such a context. Secondly, we describe
our crossed-clustering method which is applied on data generated from our data
warehouse. Our preliminary results are interesting and promising illustrating
the benefits of our WUM methods, even if more investigations are needed on the
same dataset.
