5. Motor control algorithms are still being fine-tuned
4. An apparently trivial fault can cause a cascade effect that causes the system to break down
3. Interrogating the system for diagnosis usually produces partial, uncertain information
2. Perfectly consistent internal logic, when applied to the environment, produces unanticipated results
And the Number One way a toddler is like a robot:
1. Despite the developers' best efforts, the system never behaves or develops as expected.