"The Elliott Wave Principle, as popularly practiced, is not a legitimate theory but a story, and a compelling one that is eloquently told by Robert Prechter. The account is especially persuasive because EWP has the seemingly remarkable ability to fit any segment of market history down to its most minute fluctuations. I contend this is made possible by the method’s loosely defined rules and the ability to postulate a large number of nested waves of varying magnitude.
This gives the Elliott analyst the same freedom and flexibility that allowed pre-Copernican astronomers to explain all observed planet movements even though their underlying theory of an Earth-centered universe was wrong.
The analogy between the medieval astronomer fitting epicycle upon epicycle to their data and EWP analysts fitting wave within nested wave to market data is strong. Thus, even if the fundamental notion of EWP is wrong, the method of analysis will still be able to obtain a very good fit to past data
..
By employing a large number of nested waves that can
vary in both duration and magnitude, it is possible to derive an Elliott
wave count (i.e., fit) for any prior segment of historical data."
- David R. Aronson, Evidence-Based Technical Analysis, 2007