Purpose: Show the library as a living, dynamic place. To highlight lent out books and show how peoples choices makes an impression/mark on a constantly changing surface. We also want to inspire people to borrow books in other genres and in that way broaden their perspectives.

Libraries are, from our preconceptions, a rather static environment with a lot of inherent values of quietness, respect for the knowledge kept there and things you can or can not do. Books are stored on shelves and registered in databases and such, what is not shown to the visitor is the mass of books that is not present. Absent books are noticed only when trying to find a book that has been lent out, in other words: an absent book is shown only by just that, its absence. Yet the books not present in the physical environment of the library are the ones that actually are active, sure there are books active in the library too but this is a very small quantity compared to the books that has been lent out. We consider an active book to be a book that is used by someone, i.e. not passive on a shelf. We want to visualise the absent books since these are in effect the dynamic properties of a library and what makes a library living. This is not saying that a referential library is inactive and "dead", it just has another purpose! We believe that by showing the absent books to the visitors through abstract information visualisation, the important role of the libraries as a part of the democratic process is highlighted. The dynamic character of the Book Mobile modifies the static environment by being dynamic and also creates a contrast to the square shapes that are predominant in most libraries, but not all. By visualizing the active, absent books, i a dynamic way the visitor is forced to reevaluate his or her preconceptions of a static environment and maybe most important the role of the library. Because of the character of the book mobile the visitor becomes part of the installation when loaning a book, he or she becomes part of the library.

Examples of visualisation
Because we aim to have a dynamic and constantly changing surface we don't want to limit ourselves (and the library) to only be able to visualize the book title and author perhaps. We want the library to be able to make choices that fits their "needs" and display whatever seems important so them, it could be a passage from a book, shelf placement etc.

• Each ring has a specific genre and background color, on each ring the last lent out book is projected according to genre, the size of the ring is dependent on for example the amount of loans or requests for that particular book.
• Each ring shows a random chosen book that has been lent out the latest hour for example, as in previous example the background color is dependent on genre and the size on popularity. Another version could be that the book that has been lent out in the last 15 minutes is moved to the top and automatically removes the book underneath, that creates movements in the mobile...
• Each ring corresponds to a genre or other grouping of the lent out books, for example fiction, professional literature, children's books and e-resources, amounting to 4 separate rings. The size of each ring represents the amount of lent out books etc. in that genre and the variations in height shows for example the popularity of the genre over the last week with the most popular genre at the top. This shows the whole collection of lent out books as well as trends in loaning at the same time.
• Each ring corresponds to a number and the size of the ring shows the amount of books with, at least, that number of pages. The relation in height between the rings shows the collective age of those who has borrowed the book, thus giving a nice view of the correlations between age and thickness of books.