The document discusses different components involved in web recommendation systems including preprocessing steps, interfaces, classes, and design challenges. It outlines a class diagram showing interfaces like WebRecommender and SearchEngine, and classes that implement them like YahooEngine and GoogleEngine. It also describes next steps like integrating preprocessing programs and implementing specific classes and interfaces.

2. Class Diagram setQueryFormulator(QueryFormulator qf) <<interface>> WebRecommender Recommend(Page p): List<Page> <<interface>> SearchEngine Search() : List<Page> StructureFeatureRecommender Recommend(Page p): List<Page> SemanticFeatureRecommender Recommend(Page p): List<Page> YahooEngine Search(QueryFormulator qf) : List<Page> GoogleEngine Search(QueryFormulator qf) : List<Page> <<interface>> QueryFormulator CreateQuery(List<String> ls): List<String> YahooQueryFormulator CreateQuery(List<String> ls): List<String> GoogleQueryFormulator CreateQuery(List<String> ls): List<String> <<interface>> QueryTermGenerator generateQueryTerms ( List<String> keyTerms ) : List<String> TFIDFQueryTermGenerator generateQueryTerms ( List<String> keyTerms ) : List<String> StatisticFeatureRecommender Recommend(Page p): List<Page>

3. Domain Model 1 * 1 1 1 * * * text Page url Search Engine searchEngine Term termString Query queryString