Like it was said,
sentience is a term from ancient Greek philosophy, meaning "having senses", like dogs and humans have, as opposed to plants and rocks. Many sci-fi authors like "sapient" for reasoning species, link humans and the alien races in their spacecraft. I know I like the term, but some people actually claim it's racist, having roots in the species name for humans --
homo sapiens.
They prefer the term "sophont".
One of the classical tests for self-awareness is the mirror test. You mark an animal on it's face, and show it it's reflection. If it tries to use the mirror to study the mark, it's self aware. Dogs and birds often fail the mirror test, reacting with fear or tying to otherwise interact with the image. Chimps and dolphins respond to their refection. interestingly, children tend to fail the mirror test before they're 4 years old. And I doubt a computer will ever pass.
That's the whole thing about computer intelligence. Humans and other animals crave social interaction -- infants know, that if they manipulate their surroundings, they get what they need to be comfortable. How're going to program a computer, to improve it's programming, to avoid a power drain -- it has no belly, it's never hungry, or cold or afraid of being alone.
Dogs want security of the pack, they've started with the beginnings of intelligence and we can manipulate their behavior. Horses instinctively run from fire, except for horses that pulled fire wagons, they used their sense of smell to run towards fire. Again, pack mentality allowed us to "reprogram" them. There's no way to discipline a computer.