Table 2. Feature analysis in predicting helpful reviews.

Open dataset analysis in predicting helpful reviews.

Dataset collected by/dataset name	Source	Available features	Number of reviews
Blitzer, Dredze & Pereira (2007)	Amazon	Comments, Rating, Helpful Vote, Date, Title, Product Id, Product Name, Product Type, Reviewer Name, Reviewer Location	65,222
Jure Leskovec	Stanford University Data	Product Id, Product Title, Product Price User Id, Profile Name, Helpfulness, Score, Time, Summar, Text	34,686,770
Amazon Reviews for Sentiment Analysis	Kaggle	Comments, Rating	4,000,000
Kindle Review	Kaggle	Comments, Rating, Helpful Vote, Date, Title, Product Id, Product Name, Product Type	9,882,619