Editorial
E. Férnandez

• Biased Data and its Analysis. J.L. Ojeda, J. A. Cristóbal, J. T. Alcalá
• The uniform rule in the division problem. G. Bergantiños
• Internet usage and adoption at the household level in Spain: Some thoughts for policy. J. Pérez, R. Sánchez-Mangas
• Learning processes analysis at different educational levels. A. M. Lara, Y. Román