Arabic orthography is mainly presented either in shallow orthography (with all diacritics) for novice students or in deep orthography (without diacritics) for superior readers. However, the shallow orthography is heavily loaded with diacritics which may burden the reading process, whereas deep orthography can cause ambiguity (heterophonic homographic words). Building upon the findings of current psycholinguistic research, this study introduces a systematic approach to effectively and economically address the issue of diacritics and reading. This proposed approach begins with shallow orthography for new words the first six to twelve times they are encountered to assure lexical internalization and then ends with the newly-coined term semi-deep orthography in which only the needed diacritics are used. The semi-deep orthography is employed based on two principles: word frequency and ambiguity within the root-pattern system. The first principle is word frequency, in which the top 5000 high-frequency words, accounting for approximately 90% of written discourse, do not need diacritics. The second principle is ambiguity within the root-pattern system, since this system produces nearly 85% of Arabic vocabulary and thus provides the basic unwritten-vowel framework required for reading. However, occasionally ambiguity emerges within the system, for example when diacritics are required to distinguish between the active and passive forms of a verb. [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.]