This paper describes an architecture for supporting interface attuchments- small interactive programs which are designed to augment the functionality of other applications. This architecture is designedto work with a diverse setof conventional applications, but require only a minimal setof “hooks” into thoseapplications. In order to achievethis, the work describedhereconcentrateson what we will call observational attachments, a subclass of attachments that operate primarily by observing and manipulating the surface representationsof applications that is the visual information that applications would normally display on the screenor print. Theseattachments canbethought of as“looking over the shoulderof the user” to assist with various tasks. By requiring very little modification to, or help from, the applications they augment, this approach supports the creation of a set of uniform servicesthat can be applied acrossa more diverse setof applicationsthantraditional approaches.
Dan R. Olsen, Scott E. Hudson, Thom Verratti, Jere