Olsen et al (1998). Full Text Searching and Information Overload. The International Information & Library Review, vol. 30(2), pp. 105-122:
"While the tools for writing, storing, disseminating and retrieving documents have undergone a revolution in the last few decades, reading is still a very slow process. For practical reasons, we are forced to determine a working set size, i.e., the number of documents that we can handle."
(...)
"By combining metadata and subject terms in a vector-based information space, visualization may give us the opportunity to handle larger document collections and to help the user to find the documents that are most likely to satisfy an information need defined on a pragmatic level."