A creative professional who is also known as a creative specialist is a person who is employed for the extraction of skills in creative endeavors. Creative professions include writing, art, design, theater, television, radio, motion pictures, related crafts, as well as marketing, strategy, scientific research and development, product development, engineering, some types of teaching and curriculum design, and more. Since many creative professionals (actors and writers, for example) are also employed in secondary professions, estimates of creative professionals are often inaccurate. By some estimates, approximately 10 million US workers are creative professionals; depending upon the depth and breadth of the definition, this estimate may be doubled.[citation needed]