This dataset is used to train and evaluate models for the detection of machine-paraphrased text. The training set consists of 200,767 paragraphs (98,282 original, 102,485 paraphrased) extracted from 8,024 Wikipedia (English) articles (4,012 original, 4,012 paraphrased using the SpinBot API). The test set is divided into 3 subsets: one created from preprints of research papers on arXiv, one from graduation theses, and one from Wikipedia articles. Additionally, different marchine-paraphrasing methods were used. Test sets: SpinBot: arXiv - Original - 20,966; Spun - 20,867 Theses - Original - 5,226; Spun - 3,463 Wikipedia - Original - 39,241; Spun - 40,729 SpinnerChief-4W: arXiv - Original - 20,966; Spun - 21,671 Theses - Original - 2,379; Spun - 2,941 Wikipedia - Original - 39,241; Spun - 39,618 SpinnerChief-2W: arXiv - Original - 20,966; Spun - 21,719 Theses - Original - 2,379; Spun - 2,941 Wikipedia - Original - 39,241; Spun - 39,697