The document discusses revisions that were made to Bloom's Taxonomy of Learning. The original taxonomy classified learning objectives into six levels from simple to complex. It was revised in 1999 to address criticisms and broaden its applicability. The revised version distinguishes between factual, procedural, conceptual, and metacognitive knowledge. It also changes the names of the categories from nouns to verbs to better reflect thinking as an active process. The revision emphasizes higher-order thinking and has been widely adopted to improve curriculum, instruction, and assessment.