👉 The NDF, or Non-Degree-Free Fraction, is a measure used in Natural Language Processing (NLP) to quantify the proportion of tokens in a text corpus that do not belong to degree-free categories. Degree-free tokens are those that appear only once in a text, such as individual words or unique phrases. The NDF is calculated by dividing the number of non-degree-free tokens by the total number of tokens in a corpus. This metric is crucial for understanding the complexity and richness of language in a given dataset, as degree-free tokens often indicate unique or distinctive content. By analyzing the NDF, researchers can gain insights into the diversity and complexity of language use, which is essential for tasks like text classification, information retrieval, and language modeling.
