Natural GOMS Language technique was developed by David Kieras in 1988.
[1] The motivation was to make GOMS/CCT (cognitive complexity theory) simple to use, and still keep the power and flexibility of standard GOMS.
The user's high-level goals are unfolded until only operators remain.
Since NGOMSL is based on CCT, it has certain properties that make it unique.
One operation occupies the user completely, there is no multitasking, which makes NGOMSL inappropriate for analyzing tasks where the users are under time pressure, highly practiced and, in reality, do act in a parallel fashion.