TOEFL ; Word level test ; Computer (Sprachunterricht) ; Computer (language teaching) ; CALL; E-learning; Mobile-assisted language learning; MALL ; English as a second language; ESL; TESOL ; LDV; Linguistic data processing ; Netz (semant.) ; Net (semant.) ; Semantic net ; LSA; Latent semantic mapping ; Zweitspracherwerb (lex.) ; Second language acquisition (lex.) ; Vocabulary (second language acquisition) ; English