Objectives provide direction for teaching and learning by defining what students should be able to do after instruction. Objectives aid both students and teachers by helping to plan lessons, identify appropriate activities and assessments, and provide feedback. Bloom's Taxonomy and Mager's instructional objectives frameworks classify objectives according to domains of learning and specify that objectives use action verbs to describe intended student behaviors under certain conditions and to defined performance standards. Well-written objectives are specific, measurable, achievable, realistic and time-bound to effectively guide teaching and assessment.