Problems with Hall devices for instructional use in undergraduate laboratories stimulated this investigation for development of rugged, easily constructed, inexpensive, electrically reproducible Hall devices with high output voltage. Silicon was chosen as the Hall-plate material on the basis of cost and availability. Advantages and disadvantages of various plate shapes, sizes, surface treatments, contact arrangements and types of contacts are discussed. Aluminum evaporation and electroless nickel plating were found to be satisfactory for making contact to the p- and n-type silicon plates, respectively. The final products chosen consisted of Hall plates of about 1.0 in x 0.235 in x 0.007 in which were placed on circuit board and connected by spring contact (phosphor-bronze wire) to the external circuitry. The effects of band structure, scattering mechanisms and plate geometry were considered in predictions of Hall voltage for two p-type and three n-type Hall plates. Agreement was obtained between theory and experiment to the author's satisfaction.