Reading and spelling are essential skills for a student's educational success. The current literature on spelling instruction has examined a variety of spelling modalities, but has never directly compared written versus oral spelling. There are theoretical and empirical indications that either method may be superior to the other. Thus, study one directly compared written and oral spelling instruction for their rates of spelling acquisition as well as generalization to reading. The results of study 1 indicated that written spelling was superior to oral spelling in rates of acquisition of both spelling and reading accuracy. Previous research has also indicated that spontaneous generalization can occur between reading and spelling, however, the investigations have been limited by methodological issues. Study 2 was designed to address these limitations through a comparison of reading instruction alone, spelling instruction alone, and combined reading and spelling instruction. The results of study 2 indicated that combining instruction in reading and spelling led to the most rapid rates of acquisition of spelling and reading accuracy. These findings are discussed in light of behavioral concepts such as stimulus control, complete learning trials, and generalization. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com.bibliotheek.ehb.be/en-US/products/dissertations/individuals.shtml.]