Since we noticed that three of our classifiers all ended up with about the same score, we decided to give the task to two human annotators to establish an upper bound. We selected 250 sentences for manual annotation and again removed all quotation marks. Both annotators ended up with an accuracy comparable to that of the best machine learning methods, 84% and 82.8% respectively. From this result we concluded that it is not expedient to further optimise the sentence classification task, as we had already reached human-level accuracy.