Despite substantial correlational evidence of a relationship between morphological awareness and reading ability, there has been only limited intervention research conducted to document the effects of morphological awareness on various literacy outcomes, particularly reading comprehension, and almost no research comparing the relative effectiveness of different types of morphological awareness instruction. A five-week quasi-experimental study was conducted to compare the effects of two treatments, Phonology & Spelling and Suffix & Syntax, designed to increase sixth grade students' morphological awareness on literacy outcomes. Both treatments emphasized recognition of morphological relatedness among words; however, the Phonology & Spelling treatment emphasized various patterns of phonological and orthographic shifts between related derivational word pairs and the Suffix & Syntax treatment emphasized the grammatical role and meaning of derivational suffixes. Measures included the passage comprehension subtest of the Woodcock Reading Mastery Tests (WRMT-R/NU), the Comes From Test; the Test of Morphological Structure, Part I: Derivation and Part II: Decomposition; and experimenter-designed measures of students' ability to use syntactically appropriate words, and morphological generalization; as well as related derivational spelling outcomes. In a repeated measures ANOVA of the WRMT-R/NU pre- and post-test data, the time x treatment interaction approached significance. A similar analysis of students' ability to use syntactically appropriate words resulted in a significant main effect of time; therefore, exposure to a range of suffixes may have increased both groups' awareness of syntax. Moreover, findings from an ANCOVA used to compare students' ability to use morphological generalization showed a significant advantage for the Suffix & Syntax group, partial ?[superscript 2] = 0.138. An ANCOVA of written responses to Test of Morphological Structure Part I: Derivation, as evidence of derivational spelling, indicated a significant advantage for the Phonology & Spelling group, partial ?[superscript 2] = 0.10. These results indicate that older students in the middle and upper grades may continue to benefit from spelling instruction related to morphology and changes in spelling that occur with derivational suffixing. Furthermore, instruction in grammar may help older students to better understand the syntactic cuing and meaning found in derivational suffixes and may prove useful in improving reading skills in addition to writing. [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.]