Multilingual Stemming” or “Stemming Optimized for English”?
When most documents are in English, we recommend that you choose “Stemming Optimized for English”. In this case, stemming rules only correspond to the morphology of English and they do not have to handle possible conflicts with other languages’ morphological rules. “Stemming Optimized for English” is more precise for English than “Multilingual Stemming”. On the other hand, when documents are written in more than one language (English, French, Spanish or German) “Multilingual Stemming” is more appropriate. In that case, stemming rules for the four languages are used. Special heuristics minimize the errors that are due to cross language conflicts between rules. “Multilingual Stemming” is slightly less precise for English than “Stemming Optimized for English. However, it is by far much better for French, Spanish and German.
