Low scores of minority students who performed below the standard on the seventh-grade writing test of the Texas Assessment of Knowledge and Skills (TAKS), are the basis for this study, which examines the effectiveness of Saturday Title I classes in increasing student scores on the TAKS. The treatment of instructional intervention is delivered through the Saturday Title I classes. The impact of the instruction determines its effectiveness on the student writers' performance on the TAKS 2004 versus the students' performance on the TAKS 2003. Comparing the TAKS writing scores of both benchmark years of the assessment indicated that student writers had difficulty in successfully obtaining a score by the raters of two or higher. The seventh-grade writers in this study are members of an urban school, which has 98% economically disadvantaged populations receiving free or reduced lunch benefits. For the writing subtest, these students are given prompts (topics predetermined by test administrators) to write a composition that demonstrates their ability to exhibit elements of writing based on their personal experiences. The dependent variable for this study is the student scores of TAKS 2003 and TAKS 2004. The independent variables are the instructional intervention of the Saturday Title I classes, the two ethnicities (Hispanics and African Americans), and both genders. The research used the Ex Post Facto design to examine the significance of the TAKS 2003 scores for writing to the TAKS 2004 scores. The treatment used to improve the writing scores from 2003 to 2004 is the instructional intervention of lecture and the process strategy known as critical thinking. Students are trained to evaluate their compositions based on the criteria present on rubrics used by the raters grading the compositions. The results of the study are similar to studies from the United Kingdom researchers, Feyisa Damie and Joseph Klein, as other national and international studies indicate. The findings revealed that Hispanic males improved more significantly than African American students and Hispanic females did on either the TAKS 2003 or the TAKS 2004, following the more focused instructional treatment that was delivered prior to the TAKS 2004 administration. Several recommendations were tendered for administrators to use to engage teachers to instruct students to have successful achievement on the TAKS writing subtest. [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://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]