Reading 5 - Trainable Symbol Recognizer

Paper
Kara, Levent Burak, and Thomas F. Stahovich. "An image-based, trainable symbol recognizer for hand-drawn sketches." Computers & Graphics 29.4 (2005): 501-517.
Publication Link: http://www.sciencedirect.com/science/article/pii/S0097849305000853

Notes
This paper should be useful to give a little more algorithmic background.