Bloom's taxonomy was developed in 1956 to classify the complexity of assessments in training courses and has evolved into a system for classifying learning outcomes. It remains relevant today as the basis for designing learning outcomes and is still used by instructional designers, curriculum developers, and online instructors to write learning objectives and measure online discussion quality. In 2007, Andrew Churches updated Bloom's taxonomy to introduce Bloom's Digital Taxonomy, merging Bloom's cognitive levels with 21st century digital skills and ways to incorporate Web 2.0 technologies at each cognitive level. Bloom's taxonomy continues to shape the fields of instructional design and assessment and serves as a common language for education practitioners.