Weighted least squares 6 EFFICIENT ESTIMATION 3 ESTIMACION EFICIENTE 3 LINEAR REGRESSION 3 MINIMOS CUADRADOS PESADOS 3 REGRESION LINEAL 3 ROBUSTEZ 3 ROBUSTNESS 3 WEIGHTED LEAST SQUARES 3 Adaptive estimation 2 Breakdown point 2 Compatibility 2 Efficient estimation 2 Maximum bias function 2 Maximum breakdown point 2 Newton-Raphson 2 Projections under seminorm 2 Robust statistics 2