Abstract: Mixed reality instructional technology is enhanced. Comparison of a guide mixed reality data stream to a candidate mixed reality data stream detects a deviation, e.g., different hand movement, different tool placement, or different sensor telemetry. Experiencing a feedback stream of output that is based on the deviation facilitates device control and helps candidates improve their skills. Some feedback output emphasizes deviation size, e.g., by varying colors, sounds, or haptic output proportionally to the deviation size. Some feedback output renders a translucent or skeletal guide overlaid on a live video of current candidate activity. Some embodiments support searches whose results show, e.g., how a certain expert performed a task differently than the candidate, or examples of a certain task such as widget replacement in the field. Stream optimization, summarization, synchronization, and other stream derivation functionality is provided.