May 13, 2021 Green indicates the location of the eyes, blue the location of the fingers. The darker the shade, the longer or more frequent the glances or movements. Left: simulation by the model; right: observation from a real user. The AI model can simulate how a human user would type any sentence on any keyboard design. It makes errors, detects them—though not always immediately—and corrects them very much like humans would. The simulation also predicts how people adapt to alternating circumstances, like how their writing style changes when they start using a new auto-correction system or keyboard design.