Hall effect and resistivity measurements from room temperature to 4.2 °K have been carried out on silicon samples implanted with 400-keV phosphorus, lithium, and boron ions. Implantations were carried out at 25 °C in random as well as precisely controlled channeling directions, and the electrical measurements were made after successive annealing treatments. These measurements are interpreted in terms of the final lattice position of the injected impurity ions and the amount and type of crystal defects produced during the implantation and are correlated with physical measurements of lattice position and radiation damage studied by using nuclear-reaction, beta-particle emission, and Rutherford-scattering techniques.