Many computer systems that people interact with on a daily basis require knowledge about certain aspects of the world, or models, to work. These systems have to be trained, often needing to learn how to recognize objects from video or image data. This data frequently contains superfluous content that reduces the accuracy of models. So, researchers found a way to incorporate natural hand gestures into the teaching process. This way, users can more easily teach machines about objects, and the machines can also learn more effectively.