Standardized tests provide information about student achievement that are vital to understanding how well students are learning the state standards. The problem addressed in this study was the underachievement of 52% of third-grade students in the target district in English Language Arts on a state standardized test. Poor reading skills can cause students to be in jeopardy of retention in the third grade. Poor reading and writing skills in third-grade have been a predictor of poor reading and writing skills throughout the academic career of the student. The purpose of the study was to determine the difference in the Lexile reader measure scores and the extended writing response scores for third-grade students at the target school between 2016-2018. This was not a repeated measures study because a new class of third-grade students took the GMAS each year between 2016 and 2018. The guiding theoretical framework for the study was constructivism. Social and cognitive constructivist theories are important in understanding how students gain independence in their academic skills in order for them to perform successfully on standardized tests. This quantitative, ex-post facto study used archival data to assess the reading and writing scores of 451 participants who took the state summative assessment between 2016-2018. An ANOVA and Scheffe test were used to analyze the archival data, and the null hypotheses were rejected because a significant difference was identified between both the Lexile reader measure score and the extended writing response score. The findings supported high student achievement in reading and moderate achievement in writing in the target school over a three-year period. Recommendations included further studies on constructivist pedagogy, performance of students in various demographics and analysis of the narrative writing score on the state summative assessment. [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.]