Contour drawing

I watched the video of yesterdays drawing lesson. The exercise was to daw a face, but just a contour line drawing, no shading involved. You either had a model to draw from or used a mirror and draw your own face. First, you drew the face as you saw it. The second time, you could not look at your paper while drawing and to really slow down and concentrate at looking at what you were drawing and follow the lines and curves of the subject, the third time you used the same concept of concentrating of actually drawing your subject but you could look occasionally on your paper for placement. I think I did something like this once before. I admit I didn’t actually do the exercise because it was late but wanted to see what the technique  was she was using.