Finally, |C(d)| is the number of clauses in the document d, which are defined as a "simple sentences" or, more precisely, the smallest grammatical units which can express a complete proposition 3 .
with this features/dataset combination, with the glm library we see slight rises in Precision@5, F1-Score@15 and MAP from 24% to 24.4%, from 19.22% to 20.30% and from 0.127 o 0.136 respectively; for C5.0, while F1-Score rises from 18.95% to just 19.29%, Precision@5 and MAP shows a more significant improvement from 22.2% to 26.8% and from 0.123 to 0.137 respectively, thus supposedly showing a better ranking of the keyphrases found.