Howard Gardner published a book in 1983 called Frames of Mind that outlined seven intelligences: linguistic, logical-mathematical, musical, bodily-kinesthetic, visual-spatial, interpersonal, and intrapersonal. His work was based on human psychology and not intended as an educational system, but it has become widely used in education. Each intelligence represents a different way students understand and learn, and teachers can utilize various tools and techniques to help students develop their strengths in each area.