Analysis of the cession of particulars among a Public Administration and a university for the realization of a scientific study (articles 11.2 e) and 21 LOPD and 9 RLOPD). Necessary application of the principles of quality of the data and of incompatibility of the purpose prestresses (art. 4 LOPD). Analysis of the necessary concept of scientific study and requirements to determine that we are in the face of a scientific purpose. Impossibility about handing over the data anonymized for the realization of the study, and need to respect the duty of secret during its realization and in the publication of the results.