While in case of applying semantically motivated recognition grammars the WER increases, it must be noted that in cases in which no back off models were applied this is to some extent due to OOG utterances (as these yield several deletions compared to the reference data).
even in 3 The results were: interpolated/adapted LM: WER: 13.43%, F1: 71.22%, semantic grammar + interpolated/adapted LM backoff: WER: 13.85, F1: 84.6%, syntactic recognition grammar: WER: 18.98%, F1: 70.86%, syntactic recognition grammar + trigram back off: WER: 13.98%, F1: 71.27%.