An activity assistance system includes a video camera arranged to acquire video of a person performing an activity, an output device configured to output human-perceptible prompts, and an electronic processor programmed to execute an activity script. The script comprises a sequence of steps choreographing the activity. The execution of each step includes presenting a prompt via the output device and detecting an event or sequence of events subsequent to the presenting of the prompt. Each event is detected by performing object detection on the video to detect one or more objects depicted in the video and applying one or more object-oriented image analysis functions to detect a spatial or temporal arrangement of one or more of the detected objects. Each event detection triggers an action comprising at least one of presenting a prompt via the output device and and/or going to another step of the activity script.