CRC/C/GC/24 and positive involvement of members of parliament, NGOs and the media, and support their efforts in the improvement of the understanding of a rights-based approach to children who have been or are in conflict with the penal law. It is crucial for children, in particular those who have experience with the juvenile justice system, to be involved in these awarenessraising efforts. 123. It is essential for the quality of the administration of juvenile justice that all the professionals involved, inter alia, in law enforcement and the judiciary receive appropriate training on the content and meaning of the provisions of CRC in general, particularly those directly relevant to their daily practice. This training should be organized in a systematic and ongoing manner and should not be limited to information on the relevant national and international legal provisions. It should include information on, inter alia, the social and other causes of juvenile delinquency, psychological and other aspects of the development of children, with special attention to girls and children belonging to minorities or indigenous peoples, the culture and the trends in the world of young people, the dynamics of group activities, and the available measures dealing with children in conflict with the penal law, in particular measures without resorting to judicial proceedings (see chapter V, section B and E, above). VIII. Data collection, evaluation and research 124. The Committee is deeply concerned about the lack of even basic and disaggregated data on, inter alia, the number and nature of offences committed by children, the use and the average duration of pretrial detention, the number of children dealt with by resorting to measures other than judicial proceedings (diversion), the number of convicted children and the nature of the sanctions imposed on them. The Committee urges the States parties to systematically collect disaggregated data relevant to the information on the practice of the administration of juvenile justice, and necessary for the development, implementation and evaluation of policies and programmes aiming at the prevention and effective responses to juvenile delinquency in full accordance with the principles and provisions of CRC. 125. The Committee recommends that States parties conduct regular evaluations of their practice of juvenile justice, in particular of the effectiveness of the measures taken, including those concerning discrimination, reintegration and recidivism, preferably carried out by independent academic institutions. Research, as for example on the disparities in the administration of juvenile justice which may amount to discrimination, and developments in the field of juvenile delinquency, such as effective diversion programmes or newly emerging juvenile delinquency activities, will indicate critical points of success and concern. 126. It is important that children are involved in this evaluation and research, in particular those who have been in contact with parts of the juvenile justice system. The privacy of these children and the confidentiality of their cooperation should be fully respected and protected. In this regard, the Committee refers the States parties to the existing international guidelines on the involvement of children in research. 23