[5] Nielsen's earlier affiliations include Bellcore (now known as Telcordia Technologies, formally Bell Communications Research), teaching at the Technical University of Denmark, and the IBM User Interface Institute at the Thomas J. Watson Research Center.[7][8][when?]

[9] Nielsen is on the editorial board of Morgan Kaufmann Publishers' book series in Interactive Technologies.

He holds more than a thousand United States patents,[11][12] mainly on ways of improving usability for technology.

[15] Nielsen's list of ten heuristics is probably the most-used usability framework for user interface design.

An early version of the heuristics appeared in two papers by Nielsen and Rolf Molich published in 1989-1990.

[37][38] In an interview with .net magazine, Nielsen explained that he wrote his guidelines from a usability perspective, not from the viewpoint of implementation.