Seminar by Edward Lank

Sloppy Selection:

Steering Law : Time to draw a stroke is directly proportional to length of the path and inversely proportional to width of the constrained path.
Speed of the stroke is directly proportional to width of the constrained path.

I do not remember the other law.
Both of them were used to find the intent of the user while selection using Ink.

It assumed that user selection path is more constrained if the user has to accurately select particular region/ stroke.

PUI:
Reducing the number of modes. Usually sketch interfaces plagued my the modes (writing, drawing, erase, edit...) . Method to reduce it by recognizing the user intent. Popping up tool-tip menu to identify the intent of the user and disambiguate the recognition process. e.g: A circle drawn by user can be a circle / a gesture for selection. Disambiguated by popping up "select" at tooltip. If user clicks on 'select', take selection mode or recognize stroke as circle.