Automated writing evaluation (AWE) software is designed to provide instant computer-generated scores for a submitted essay along with diagnostic feedback. Most studies on AWE have been conducted on psychometric evaluations of its validity; however, studies on how effectively AWE is used in writing classes as a pedagogical tool are limited. This study employs a naturalistic classroom-based approach to explore the interaction between how an AWE program, MY Access!, was implemented in three different ways in three EFL college writing classes in Taiwanand how students perceived its effectiveness in improving writing. The findings show that, although the implementation of AWE was not in general perceived very positively by the three classes, it was perceived comparatively more favorably when the program was used to facilitate students’ early drafting and revising process, followed by human feedback from both the teacher and peers during the later process. This study also reveals that the autonomous use of AWE as a surrogate writing coach with minimal human facilitation caused frustration to students and limited their learning of writing. In addition, teachers’ attitudes toward AWE use and their technology-use skills, as well as students’ learner characteristics and goals for learning to write, may also play vital roles in determining the effectiveness of AWE. With limitations inherent in the design of AWE technology, language teachers need to be more critically aware that the implementation of AWE requires well thought-out pedagogical designs and thorough considerations for its relevance to the objectives of the learning of writing.