Lemma (text analytics) refers to the process of determining the base form of a word. For example, the words “walk,” “walks,” “walking,” and “walked” all have the same lemma, “walk.”
Lemma is closely similar to stemming, but there are some important differences. Stemming typically involves chopping off suffixes to get to the root form of a word, whereas a lemma takes into account the meaning of a word. For example, the words “better” and “worst” have the same stem (bet), but they have different lemmas (good and bad, respectively).
Different Methods used to Calculate Lemma
There are a few different methods that can be used to calculate a lemma. One common method is to use a morphological analyzer, which is a type of software that includes a database of words and their roots. Another method is to use a rule-based approach, which involves defining rules for how to find the root form of a word based on its spelling and meaning.
Lemma vs. Related Terms
Lemma is closely related if not similar to other terms such as root words and stems, but there are some important differences. Root words are the basic form of a word, without any suffixes or prefixes. Stems are the part of a word that remains after all affixes have been removed. However, unlike root words and stems, lemmas take into account the meaning of a word. For example, the words “better” and “worst” have the same stem (bet), but they have different lemmas (good and bad, respectively).
In short, a lemma is the base form of a word that includes the meaning of the word. It helps reduce the number of unique words in a text, which can make text analytics tasks easier to perform. It can also help determine the meaning of a word in a particular context.