Evaluation results of the sentiment classifiers.

The dataset sizes in the second column, used for training the classifiers, are the result of merging multiple annotated tweets (there was no merging for the Facebook(it) and DJIA30 datasets). The 95% confidence intervals for Alpha are estimated from 10-fold cross-validations. The last row is an evaluation of the general English language model (trained from the English dataset in row 3) on the Environment dataset.