SUBJECT: Hierarchical Corpuses &NAME , I am looking for a large hierarchical corpus of text documents , for a research in the field of hierarchical classification . I would like to get your opinion about the followings : &NUM &NAME - &NAME Collection Version &NUM . Is it 's hierarchy deep enough to make a point when it comes to showing the dependency of classification results on the hierarchical structure of the corpus ? &NUM &NAME - Open directory project . Why are there no researchs refering to data from the &NAME ? &NUM &NAME ! - There are several works done on data which was gathered from &ORG's science hierarchy . How can I get a copy of it ? Do I need &ORG's permission ? How do I get it ? &NUM US Patents - Where can I get this one ? &NUM Any other suggestions ? Since I could not find many research works using the &NAME corpus , even though it looks like a good one for a comparison bassis among works in the field , and several works are using &ORG's science hierarchy , it seems like a good idea to have both tested and put into the research . Looking Fwd to getting your comments on those thoughts , &NAME &NAME &NAME University .