Li, Bo (normalisation)

$$dis_{norm}(x, y) = \frac{2 \cdot dis(x,y)}{|x| + |y| + dis(x, y)}$$

Open question 🤔

$$dis_{norm}(a, b) = \frac{2 \cdot dis_{Lev}(a, b)}{|a| + |b| + dis_{Lev}(a, b)} = \frac{2}{3}$$

a and b are two different strings, shouldn’t distance be 1. For comparison Levy et al. (normalisation) is 1 in this case.

Reading

• Yujian, Li and Liu Bo. “A Normalized Levenshtein Distance Metric.” IEEE Transactions on Pattern Analysis and Machine Intelligence 29 (2007): 1091-1095.