During our working session at the Big Data school, the Spanish students had the opportunity to share their knowledge with the rest of the participants. In addition, Professor Carlos, the project organiser, gave training sessions to the teachers from other countries. The Spanish students guided the other students to create and explain datasets using WEKA, a popular tool for data analysis. They showed us how to identify relevant and reliable data sources, and how to use WEKA to extract and transform the information into a usable format. We also learned about the data analysis algorithms available in WEKA. They explained how to select and apply different algorithms for tasks such as classification, regression and clustering. We practised with real examples, which allowed us to see how algorithms can help to extract valuable insights from data. This working session not only provided us with essential technical skills in using WEKA and understanding algorithms, but also fostered the exchange of knowledge and experiences between participants of different nationalities. The experience was highly interactive and enriching, providing us with practical tools that we will be able to apply in future Big Data projects. n the conservation of endangered species and the restoration of marine habitats.