The browse collection screen provides an overview of th ecollections on a timeline, selected filters, and a textual list of the collections which can be sorted by date, topic, formats etc. There is tight coupling between the 3 parts of the display. When the filters are used the timeline and the list shows only the collections who answer the query. When the cursor is placed on a collection the timeline bar, the title of the collection and the attributes of the collections are highlighted. The short descriptionof the collection appears at the bottom of the screen. After using the filter user can further reduce the set of collections by manual deselecting them. The remaining set of selected collections becomes the scope of the search when using the "Search selected collections" feature (see search tab on the left side of the screen). This set of selected collection would also appear as the scope in the refined seach screen (but that's not working in this prototype). DATA We used the data given to us by LC about 5 real collections and added several other "fake" collections for testing purposes. GRAPHIC OVERVIEW Each bar represents a collection and indicates the scope of the collection. The interval field can be panned and zoomed by manipulating the double-box slider beneath the timeline. The Y axis has no meaning. We considered Size of the collection for the Y axis but the team was reluctant to define a size for each collection (is size the number of items, byte size, time to evaluate?). Instead, the intervals would simply be iterated in a non-overlapping manner down the vertical axis of the interval-field. Of course a better "packing" algorithm will need to be applied as the number of collection grows. Color-coding schemes for the intervals were also considered, and rejected. Most of the attributes for the collections can assume multiple values. For example, the Format attribute can be any combination of Text, Film, Sound, etc., so a single color code would not be appropriate. JAVA IMPLEMENTATION The Java prototype has three main components: the Collection Overview, the Collection Filters, and the Collection List. The use of Java allowed the Collection Overview and Collection List to dynamically change in response to collection filters, showing only those that satisfy the filter constraints. Furthermore, the Collection Overview itself acts as a filter. Panning or zooming on a particular interval of time specifies a temporal constraint, potentially filtering out more collections. The three interface components are linked via an active cursor. Passing the cursor over a collection interval or collection name highlights the other, as well as the appropriate attributes in the Collection Filters. The URL for the collection homepage is displayed in the status bar. Pressing the mouse button causes a jump to the collection homepage. Each collection has its attributes defined in a text file which is read by the Java Applet at the start of the search and browse session. The file defines the name and dates of each collection, and any number of attributes. Collections can be edited, added, or removed, and the interface will reflect these changes at the start of the next session. The Collection List can be sorted on any of the collection attributes. The use of Java allows interface objects to be created dynamically, based on the contents of a text file that defines the collections. Java facilitates the active linking between components, links to homepages, and collection sorting. Most importantly, Java facilitates dynamic queries by allowing each discrete user event, such as a mouse moving a slider, to be intercepted and processed, triggering a re-draw of the visualization of results. This tight coupling of user events to graphical re-drawing is fundamental to dynamic queries.