Benjamin Bloom developed the Bloom's Taxonomy model in the 1960s to classify educational learning objectives into domains. The taxonomy divides objectives into three domains: cognitive, affective, and psychomotor. The cognitive domain involves knowledge and intellectual skills development and is broken into six categories of increasing difficulty from remembering to evaluating. The affective domain deals with emotions, attitudes and values, and its categories range from receiving phenomena to internalizing values. The psychomotor domain concerns physical movement and motor skills development, with categories from imitation to origination. Bloom's Taxonomy provides a framework for instructors to set learning objectives at different levels of complexity.