Question: What datasets are chosen for the experiment?
Evidence: We evaluate the quality of the document embeddings learned by MPAD on 10 document classification datasets, covering the topic identification, coarse and fine sentiment analysis and opinion mining, and subjectivity detection tasks. We briefly introduce the datasets next. Their statistics are reported in Table TABREF21.
(1) Reuters. This dataset contains stories collected from the Reuters news agency in 1987. Following common practice, we used the ModApte split and considered only the 10 classes with the highest number of positive training examples. We also removed documents belonging to more than one class and then classes left with no document (2 classes).
(2) BBCSport BIBREF30 contains documents from the BBC Sport website corresponding to 2004-2005 sports news articles.
(3) Polarity BIBREF31 features positive and negative labeled snippets from Rotten Tomatoes.
(4) Subjectivity BIBREF32 contains movie review snippets from Rotten Tomatoes (subjective sentences), and Internet Movie Database plot summaries (objective sentences).
(5) MPQA BIBREF33 is made of positive and negative phrases, annotated as part of the summer 2002 NRRC Workshop on Multi-Perspective Question Answering.
(6) IMDB BIBREF34 is a collection of highly polarized movie reviews from IMDB (positive and negative). There are at most 30 reviews for each movie.
(7) TREC BIBREF35 consists of questions that are classified into 6 different categories.
(8) SST-1 BIBREF36 contains the same snippets as Polarity. The authors used the Stanford Parser to parse the snippets and split them into multiple sentences. They then used Amazon Mechanical Turk to annotate the resulting phrases according to their polarity (very negative, negative, neutral, positive, very positive).
(9) SST-2 BIBREF36 is the same as SST-1 but with neutral reviews removed and snippets classified as positive or negative.
(10) Yelp2013 BIBREF26 features reviews obtained from the 2013 Yelp Dataset Challenge.
(1) Reuters. This dataset contains stories collected from the Reuters news agency in 1987. Following common practice, we used the ModApte split and considered only the 10 classes with the highest number of positive training examples. We also removed documents belonging to more than one class and then classes left with no document (2 classes). (2) BBCSport BIBREF30 contains documents from the BBC Sport website corresponding to 2004-2005 sports news articles. (3) Polaritity (Pang and Lee 2005) features positive and negative labeled snippets from Rotten Tomatoes. (4) Subjectivity (Pang and Lee 2004) contains movie review snippets from Rotten Tomatoes (subjective sentences), and Internet Movie Database plot summaries (objective sentences). (5) MPQA  (Wiebe, Wilson, and Cardie 2005) is made of positive and negative phrases, annotated as part of the summer 2002 NRRC Workshop on Multi-Perspective Question Answering. (6) IMDB (Maas et al. 2011) is a collection of highly polarized movie reviews from IMDB (positive and negative). There are at most 30 reviews for each movie. (7) TREC (Li and Roth 2002) consists of questions that are classified into 6 different categories. (8) SST-1 (Socher et al. 2013) contains the same snippets as Polarity. The authors used the Stanford Parser to parse the snippets and split them into multiple sentences. They then used Amazon Mechanical Turk to annotate the resulting phrases according to their polarity (very negative, negative, neutral, positive, very positive). (9) SST-2 (Socher et al. 2013) is the same as SST-1 but with neutral reviews removed and snippets classified as positive or negative. (10) Yelp2013 (Tang, Qin, and Liu 2015) features reviews obtained from the 2013 Yelp Dataset Challenge.
Answer: The chosen datasets are：(1) Reuters. (2) BBCSport. (3) Polarity .(4) Subjectivity. (5) MPQA. (6) IMDB. (7) TREC. (8) SST-1. (9) SST-2. (10) Yelp2013.