An art school is an educational institution with a primary focus on the visual arts, including fine art – especially illustration, painting, photography, sculpture, and graphic design. Art schools can offer elementary, secondary, post-secondary, or undergraduate programs, and can also offer a broad-based range of programs (such as the liberal arts and sciences). There have been six major periods of art school curricula, and each one has had its own hand in developing modern institutions worldwide throughout all levels of education. Art schools also teach a variety of non-academic skills to many students. History Nicholas Houghton identifies six definitive historical art-school curricula: "apprentice, academic, formalist, expressive, conceptual, and professional". Each of these curricula have aided not only the way that modern art-schools teach, but also how students learn about art. Art schools began being perceived as legitimate universities in the 1980s. Before this, any art programs were used purely as extracurricular activities, and there were no methods of grading works. After the 1980s, however, art programs were integrated into many different kinds of schools and universities as legitimate courses that could be evaluated. While some argue that this has weakened creativity among modern art-students, others see this as a way to treat fine arts equally in comparison with other subjects. Apprentice curriculum Apprentice paths teach art as a mixture of aesthetic and function. Typically, students would apprentice themselves to someone who was already skilled in some sort of trade in exchange for food and housing. Many of the Old Masters received training in this manner, copying or painting in the style of their teacher in order to learn the trade. Once the apprenticeship ended, the student would have to prove what they learned by creating what we know today as a "masterpiece". In modern schooling, this can be seen in practical art classes, including photography or printmaking. Academic curriculum Academic curricula began during the sixteenth-century Italian Renaissance, in which some of the earliest art academies were established. Up through the nineteenth century, these academies multiplied through both Europe and North America, and art began to become about both talent and intellect. Formalist curriculum The formalist curriculum began in the mid-twentieth century, and focused on the basic components of artwork, such as "color, shape, texture, line - and a concern with the particular properties of a material or medium". This curriculum is most noted for including the height in popularity of