The phrase, "Oh, that's academic!" tends to mean "Forget about it! That's boring and unimportant!" Yet that isn't what teachers mean when they ask for "academic writing." Instead, professors tend to define academic writing as research-based, objective and formal in style and tone, thesis-driven, and deductively organized (that is, where your introduction presents your argument or interpretation and forecasts the organization for the paper).
Genres of academic writing commonly assigned in introductory composition courses in the U.S. tend to rely on exposition and analysis, including personal narratives, Book Reviews, Literacy Narratives, Reports on subjects and concepts, Rhetorical Analysis, causes and effects.
While U.S. institutions differ in how they teach composition, when schools have two rather than one introductory courses for first-year students, the second composition course tends to stress argumentation and persuasion such as classical argument, Rogerian argument, and academic research. Other common assignments include literary criticism, the in-class essay, annotated bibliography, and reflective letter, which is often associated with a students' body of work and reviewed by one or more professors.
Historically, professors have assigned "the teacher as examiner audience" or "peers in a class" yet now that the Internet has opened the classroom door to the world, many teachers have redesigned their assignments and challenged students to address real audiences--from governmental figures to readers of journals and magazines or audiences of particular online writing spaces. As discussed in New Media, the next major move for colleges is to begin preparing students for new academic genres, such as blogs, wikis, and multimedia compositions.