Intelligent Computer Assisted Language Learning (ICALL) uses advanced technology to provide customized learning and individualized feedback to foreign language students (Heift & Schulze, 2007). Some comprehensive ICALL programs claim the ability to take learners from no knowledge of a language to levels of advanced knowledge and comprehension. The websites of two such programs, Rosetta Stone and Tell Me More, state that their software is used in tens of thousands of schools worldwide. However, little if any research has been conducted to assess the effectiveness of these programs on student achievement when they supplement existing curricula. This study investigated the effect the Tell Me More program may have on achievement scores when used to supplement classroom instruction. The study also analyzed the effect on different levels of learners (non-honors and honors). The participants were 251 students of Spanish and French at a suburban high school. The study used a switching replications design involving two groups measured repeatedly over time through a standardized computer-adaptive test. Results indicated no effect of the program on achievement scores beyond that of classroom teaching and no difference between non-honors and honors students in how scores changed. Students using the program grew similarly to students not using the program during the same time-period. The findings suggest that ICALL programs may be used at all learning levels with the expectation that achievement will improve. ICALL may be assigned to build achievement outside of class so more time in class can be devoted to developing language proficiency. [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.]