This is the dataset used in the following paper: Soumi Dutta, Vibhash Chandra, Kanav Mehra, Asit Kumar Das, Tanmoy Chakraborty, Saptarshi Ghosh. Ensemble Algorithms for Microblog Summarization. IEEE Intelligent Systems (Special Issue on Summarization of Things), vol. 33, no. 3, pp. 4--14, May/June 2018. The dataset contains four sets of tweets posted during four different disaster events, and summaries written by three human annotators for each tweet-set. The dataset can be used for evaluating algorithms for microblog summarization. The included README file giving a detailed description of the dataset.