Welcome to VISVIP

VISVIP is part of the WebMetrics tool set: software designed to assist usability engineers (UE) evaluate web-based applications. The purpose of VISVIP is to visualize data generated by the WebVIP tool. WebVIP allows the UE to instrument a website so as to produce a log of activity when an experimental subject uses the site to accomplish some task. The log is essentially a sequence of time-stamped URLs, indicating the user's path through the website.

VISVIP allows the UE to visualize such paths; it automatically lays out a 2D graph of the website. Each node of the graph represents a web page, and edges represent links between pages. Nodes are color-coded by type: blue for HTML, purple for directories, green for images, and so on. Because URLs tend to be long, a briefer nickname is generated for each page. The UE has several options to simplify the graph: nodes of a given type, or those not on or near a userpath, can be suppressed. Also, if a graph is highly interconnected, the UE can specify that the site be pictured as a tree emanating from a selected root node.

Once a satisfactory graph of the website has been obtained, the UE can select which userpaths to display. These paths are represented as spline curves, resting on the plane of the website graph. The time spent at each page is depicted as a dotted vertical line with its base at the appropriate node. Curvy vertical arrows into and out of the plane mark the beginning and end of each user path. Each user is assigned a unique color, so that several paths can be shown at once.

Paths resulting from simple layout over the website are often much more complex geometrically than their inherent structure would dictate. Therefore VISVIP can also arrange the graph by treating pages as adjacent iff they are connected by a userpath, rather than by the existence of a static link. The resulting display usually makes the structure of the path much simpler, albeit at the cost of complicating the display of the underlying website.

VISVIP is brought to you by the Visualization and Usability Group of NIST. Send questions to Joe Konczal.