CFA Level I · CFA Level I Exam · Introduction to Financial Data Science
A data scientist wants to reduce the words "earned", "earning" and "earnings" to a common base form, using a rule-based procedure that strips suffixes and may produce a non-dictionary token such as "earn" or "earnin". Compared with lemmatization, this procedure is most likely:
The procedure described is stemming, which is less computationally costly but less accurate than lemmatization. It strips suffixes by rule and can output non-dictionary tokens. Lemmatization uses morphological analysis to return valid base words, so it is more accurate but more expensive.
- Amore computationally costly and always returns valid dictionary words
- Bless computationally costly and less accurateCorrect
- Cequivalent in output because both use morphological analysis of each word
Explanation
The described procedure is stemming. It applies simple suffix-stripping rules, so it is cheaper than lemmatization but can yield non-words and be less accurate. Lemmatization uses morphological analysis to return valid base forms and costs more.
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