From the animals’ perspective, the past half-century has not been one of uninterrupted progress. Indeed, as some conditions have improved, others have remained frustratingly unchanged, and still others have undoubtedly deteriorated.
How then to assess progress and failure? In the absence of a universally accepted, consistently applied set of standards for data collection and analysis, any attempt to answer the question, What is the state of animals in 2001?, must be based on a series of snapshots, an accumulation of statistics from which we can draw conclusions.
Irwin, P.G. (2001). Overview: The state of animals in 2001. In D.J. Salem & A.N. Rowan (Eds.), The state of the animals 2001 (pp. 1-19). Washington, DC: Humane Society Press.