This study is an investigation of the effects of linguistic features on quality of second language (L2) writers' essays for writing course placement at Indiana University Bloomington (IUB), and by implication at other universities and colleges. This study addresses the following research questions: (1) To what extent do selected linguistic features of narrative (Model I) and argumentative (Model II) essays predict L2 students' performance on a representative university holistic writing placement test?; (2) To what extent is the writing topic related to L2 students' argumentative writing quality as revealed by holistically scored ratings?; (3) Can differences of linguistic features predict performance in the production of narrative and integrated argumentative writings of L2 students? The ordinal logistic regression method was employed to answer the questions. The results demonstrated that there was no evidence that selected linguistic indices had statistically significant effects on the quality of L2 students' narrative writings. The results presented that there was evidence that type-token ratio (TTR), adjacent overlap noun sentence, synonym overlap sentence noun, synonym overlap paragraph noun, and repeated content lemma were significant linguistic features on the effects of L2 students' integrated argumentative writing quality. Statistical effects of topic on L2 students' argumentative writing were not identified. The results of this study shed significant light on more rationale for including integrated argumentative writing tasks on a L2 writing placement test. The results provide meaningful insights into helpful L2 writing teaching and 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.]