Table 2.

Feature Types with Examples from the Feature Set

Feature type	Number of features	Example features
Length features	15	Number of words Number of paragraphs Number of sentences
Occurrence features	30	Number of nouns Number of formal words Number of unique nouns
Error features	9	Error ratio Grammar error ratio Punctuation error ratio
Morphological complexity features	11	Number of finite verbs Number of non-third person singular verb Ratio of comparatives
Cohesion features	8	Number of connectors Number of unique connectors Mean noun overlap with previous sentence
Readability features	15	Flesch score Integration cost Average number of sentences per 100 words
Lexical diversity features	59	Type-token ratio Type-token ratio lexical words Global edit distance
Lexical sophistication features	62	BNC easy word ratio SUBLEX easy word ratio Brown Frequencies lexical word ratio
Syntactic complexity features	6	Number of subordinate clauses Number of fragment sentences Mean tokens before main verb