Writing places heavy demands on students' cognitive capacity. Existing research suggests that planning before writing can help to alleviate this cognitive burden; thus improving the quality of student writing. In this explanatory sequential mixed-methods study, the researcher examined the efficacy of specific pre-planning tools on students' paragraph writing by assessing the pre-and post-writing assessment scores of students who were assigned to three different conditions- a group who planned their paragraph by using a Single-Paragraph Outline (SPO), which is a linear outline, a group that planned their paragraph by using a concept map, and a group that did not plan their paragraph with a specific planning tool. Through post-assessment questionnaires and semi-structured interviews, the researcher gained insights into students' perceptions of the writing tools. Based on the statistical analysis of the pre-and post-assessment scores, students who planned their writing with an SPO outperformed students who planned with a concept map and students who did not use a planning tool. [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.]