Believing that problems high school students have writing academic essays is conceptual, more than skill-based, I conducted a qualitative study to investigate whether there were developmental differences in the way high school students of varying performance levels conceptualized academic essay writing. Although I found three levels of conceptualization, students at all three levels did not provide strong support for their claims, did not develop their ideas well, ignored logical relationships, had few arguments, poor coherence, poor organization, failed to make their connections clear, and used a telling rather than reasoning strategy. This book examines the ways in which the formulaic and prescriptive nature of their writing instruction adversely affected students' conceptualizations of academic essay writing, their composing strategies, and ultimately, the quality of their writing. This book offers alternatives to using the five-paragraph essay structure to teach writing and would be ideal for high School English teachers, those working in teacher preparation programs, and anyone else interested in academic essay writing and writing development.