Suchman, Lucy. (1999) - "Embodies Practices of Engineering Work".

Bodker (1996) has proposed an analysis of the use of computer applications in terms of the relation of an application to its object:

The object of activity is present only in the application.

The object exists as a physical object but is present in the use activity as the rendition provided by the computer application. (e.g. Andrea's object of activity-earth)

The object is physically co-present outside the application.