Ben Shneiderman.
The Eyes Have It: A Task by Data Type Taxonomy for Information Visualizations.
In IEEE Symposium on Visual Languages, 1996, pp. 336--343, 1996.

Bibtex:

@InProceedings{ shneiderman:1996:TEHI,
  author = 	"Ben Shneiderman",
  title = 	"The Eyes Have It: A Task by Data Type Taxonomy for
                  Information Visualizations",
  booktitle = 	"IEEE Symposium on Visual Languages, 1996",
  pages = 	"336--343",
  year = 	"1996",
}