Defining and assessing sentience

Precisely what is meant by the term sentience and how does it overlap with being conscious?We accept that animals have feelings but how do we know what they are and can we measure them?It is important that we clarify the terminology underlying these difficult concepts.Over the last 50 years a scientific discipline has developed to tackle these questions in a systematic way.We have to avoid thoughtless anthropomorphism yet we have to try to relate sentience in animals, as appropriate, to corresponding experiences in humans.