Writing across the curriculum (WAC) is a movement within contemporary composition studies that concerns itself with writing in classes beyond composition, literature, and other English courses. According to a comprehensive survey performed in 2006–2007, approximately half of American institutes of higher learning have something that can be identified as a WAC program. In 2010, Thaiss and Porter defined WAC as "a program or initiative used to 'assist teachers across disciplines in using student writing as an instructional tool in their teaching'". WAC, then, is a programmatic effort to introduce multiple instructional uses of writing beyond assessment. WAC has also been part of the student-centered pedagogies movement (student-centered learning) seeking to replace teaching via one-way transmission of knowledge from teacher to student with more interactive strategies that enable students to interact with and participate in creating knowledge in the classroom. This page principally concerns itself with WAC in American colleges and universities. WAC has also been important in Britain, but primarily at the K–12 level.

History of WAC David Russell traces the history of WAC in the United States to the 1870s, the emergence of professional disciplines, and the new need for college-level instruction in writing. Prior to this era, college students were exclusively (for all practical considerations) affluent white men whose natural discourse was identical to the approved discourse of the academy; therefore, their way of speaking and writing was already considered appropriate by and for the academy and composition didn't need to be taught at the college level. Two changes happened to motivate the need for college writing instruction. Firstly, as disciplines (as divisions within academic studies) and contemporary professions specialized, they developed their own specialized discourses. Because these discourses were not merely the same as the everyday discourse of the upper classes, they had to be taught. Secondly, as college students became more diverse – first in terms of social background and, later, in terms of gender, race, and age – not all college students grew up speaking the accepted language of the academy.

First-year composition courses couldn't be about the content of the writing, because content was what the other disciplines taught. Composition, therefore, had to be about the form the writing took and so "writing" was reduced to mechanics and style. Because of this reduced focus and because writing was addressed by composition, other disciplines assumed no responsibility for writing instruction; most students, then, were not taught to write in the context of their specialties. As American education became increasingly skills-oriented following World War II – in part a reaction to the suffusion of universities with war veterans in need of job training, in part a result of modeling education after the efficiency of Fordian factory production – writing instruction was further reduced to a set of skills to be mastered. Once correct (that is, standard academic) grammar, punctuation, spelling, and style were mastered – preferably before reaching the post-secondary level – there was no need for additional writing instruction save as remedial education.

This product-oriented, skills-focused paradigm of writing pedagogy began to change in the 1970s with the popularization of James Britton and colleagues' expressivist school of composition, which said that students benefited from writing as a tool for self-expression and that focusing on technical correctness was damaging. Janet Emig's 1977 article "Writing as a Mode of Learning," grounded in constructivist theories of education, suggested that writing functioned as a unique and invaluable way for students to understand and integrate information. Simultaneously, widespread media attention around college students' apparently decreasing writing proficiency (more a product of the changing demographics of college students than an overt shift in teaching) provoked institutions of higher learning to reevaluate and increase the amount of writing required of students. Carleton College and Beaver College began what were probably the first contemporary WAC programs in 1974 and 1975, respectively, with faculty workshops and writing requirements shared across disciplines.

Major Theories WAC efforts are usually driven principally by one of two theories: writing to learn or on learning to write in disciplinary discourses, sometimes also called writing in the disciplines. Though both may be used together, one of the two theories generally guides any given writing assignment and, often, any given WAC course.

Writing to Learn Writing to learn is also occasionally referred to as the expressionist or cognitive mode of WAC. Writing to learn supports the use of mostly informal, often ungraded writing exercises to help students understand course content in non-English disciplines. Writing to learn assumes that being able to explain or express concepts in one's own words both builds and reflects understanding. Because the goal of writing to learn exercises is learning rather than a finished writing product, instructors are discouraged from paying attention to grammar and surface mechanics. The student himself or herself, not the teacher, is the audience. Common writing to learn exercises include reading responses, journals, free writing, and multiple forms of collaborative writing.

Writing to Engage Writing to engage stands between the two most common approaches to writing across the curriculum: writing to learn and writing in the disciplines. Writing to engage involves the use of writing activities and assignments to engage students in the processes and approaches typical of a discipline and, in particular, to employ critical thinking skills typically used in that discipline. The critical thinking skills typically referred to in work on writing to engage draw on the taxonomy of educational objectives in the cognitive domain developed by Benjamin Bloom and his colleagues in the 1950s and later modified by Loren W. Anderson and David R. Krathwohl in the 1990s. Within writing studies, writing has long been viewed as a useful means of demonstrating critical thinking and, through the work of scholars such as Marlene Scardamalia and Carl Bereiter (1987), even as a means of transforming knowledge. Writing to engage takes this view of writing and applies it to WAC.

This category of WAC activities and assignments allows instructors to distinguish between writing-to-learn activities that focus largely on remembering, understanding, and reflecting and writing-to-engage activities that involve applying, analyzing, and evaluating. This focus on critical thinking supports alignment between the curricular goals of a course and instructor expectations about the kinds of work they assign. It also calls instructor attention to the development of the general and disciplinary critical thinking skills students encounter as they progress from lower-division to upper-division courses. Distinguishing between writing to learn and writing to engage can contribute in useful ways to student learning and to preparation for further work in their disciplines.

Writing in the Disciplines Writing in the disciplines is also occasionally referred to as the transactional or rhetorical mode of WAC. Writing in the Disciplines (WID) teaches students how to write acceptably in their respective disciplines. Writing in the Disciplines classes teach students to learn to write texts that they will apply in their scholarly and professional lives. Although WID and WAC are correlated, WID emphasizes disciplinary orientation. The students' participation in their majors enlists the students in discourse communities, which are social groups that communicate, at least in part, via written texts and share common goals, values, and writing standards. These writing standards include but are not limited to specialized vocabularies and particular genres.> The goal of WID is to allow students to demonstrate writing skills within the genres expected in academic and professional discourse communities.

Reflection is considered an essential component of critical learning and problem solving, and as such, is indispensable for Writing in the Disciplines. Reflection tasks stimulate students to look back on completed tasks such as writings done in their respective disciplines with the aim to understand their accomplishments and steer future actions. Students are commonly asked to work out these reflections in a writing task. The act of writing itself promotes learning in a particular discipline. They also find writing within a discipline leads students to deploy different productive approaches to learning that they might not have otherwise applied.

Writing in the discipline courses are commonly referred to as Writing Intensive courses (WI). Writing Intensive courses were developed for two reasons: 1) Students' writing skills would decrease if not consistently reinforced. 2) Students' writing improves significantly when they write involving their major. The controversy surrounding WID is who holds responsibility for teaching WID courses. The different models for teaching WID classes are the following: 1) The English (or Writing) department faculty teaches writing courses focused on individual disciplines. 2) English (or Writing) departments and other discipline departments collaborate on instructing writing courses for particular majors. Peterson talks about how English assignments done in the freshman year will carry on and relate to the writing assignments during the rest of ones college career. What is learned in one course can carry on to other courses. This knowledge can be spread by working with colleagues in the same and other departments on assignments and class discussions. By doing this, departments can learn about the similarities and differences they have between them. 3) Individual faculty of respective disciplines teach writing for their respective disciplines. Each university decides which model works best for their institution. For example, The University of San Francisco has implemented model one to teach their Writing in Psychology course(RHET 203). Cornell University has used model two to teach their Technical Writing course(WRIT 7100). The University of Missouri employs the third model to teach their Process Synthesis and Design course - Writing Intensive(CH_ENG 4980W).

WID across the Globe The University School of Business Administration (EAN) of Bogotá, Colombia, conducted a study where students took courses for writing in the disciplines. The study showed that writing in the disciplines had positive outcomes on students' performance. Students were split into writing courses based on their majors that would ultimately help them with discipline-specific writing. Courses offered for writing in the discipline included: Introduction to Administration, Principles and Theories of International Business, Economic Thought, Models of Organizational Communication and Foundation in Engineering. Not every major is the same, and there were some differences, the courses offered individual "work guides" for students so that they could focus more in-depth on writing in the discipline. The goal of this study was to help students read and write more critically and analytically.

WID in the US