Table 4.

Results for automatic keyword extraction using different algorithms.

Method	Automatic extraction		Correct keywords		Precision (%)
	Total	Mean	Total	Mean
Improved TextRank	500	5	266	2.66		53.2
Original TextRank	500	5	151	1.51		30.2
Improved TF-IDFa	500	5	133	1.33		26.6
Original TF-IDF	500	5	206	2.06		41.2

^aTF-IDF: term frequency–inverse document frequency.