Encoding Nominal (class) Values Number of classes: Normalized High: Normalized Low: One of N (One Hot) Encoding Equilateral Encoding For more information on this technique: My blog post on Equilateral Encoding Masters, T. (1993). Practical neural network recipes in C++. Morgan Kaufmann. Guiver, J. P., & Klimasauskas, C. C. (1991). Applying neural networks, Part IV: improving performance. PC AI Magazine, 5, 34-41.