Summary: This dataset contains electroencephalographic (EEG) recordings of 24 subjects doing a visual P300 Brain-Computer Interface experiment on PC. The visual P300 is an event-related potential elicited by visual stimulation, peaking 240-600 ms after stimulus onset. The experiment was designed in order to compare the use of a P300-based brain-computer interface on a PC with and without adaptive calibration using Riemannian geometry. The brain-computer interface is based on electroencephalography (EEG). EEG data were recorded thanks to 16 electrodes. A full description of the experiment is available at https://hal.archives-ouvertes.fr/hal-02103098. Data were recorded during an experiment taking place in the GIPSA-lab, Grenoble, France, in 2013 (Congedo, 2013). Python code for manipulating the data is available at https://github.com/plcrodrigues/py.BI.EEG.2013-GIPSA. The ID of this dataset is BI.EEG.2013-GIPSA. Full description of the experiment and dataset: https://hal.archives-ouvertes.fr/hal-02103098 Principal Investigator: B.Sc. Erwan Vaineau, Ph.D. Alexandre Barachant Technical Supervisors: Eng. Anton Andreev, Eng. Pedro. L. C. Rodrigues, Eng. Grégoire Cattan Scientific Supervisor: Ph.D. Marco Congedo ID of the dataset: BI.EEG.2013-GIPSA