State of the art ; Language testing ; Needs assessment (language testing) ; Second language acquisition (language teaching) ; Zweitspracherwerb (Unterricht) ; Foreign language teaching ; DaF; Deutsch als Zweitsprache; German as a second language; DaZ; German as a foreign language ; Glottodidaktik; Lehrforschung; Pädagogische Linguistik; Pedagogical linguistics; Language teaching research ; German