We strongly recommend reading the AKC breed standard as the beginning of your study of this or any breed. The standard refers to the PWD as "This highly intelligent utilitarian breed... an indelible impression of strength, spirit, and soundness".
Size - Males 20 to 23 inches (22 ideal). Females 17 to 21 (19 ideal)
Weight - Males 42 to 60 pounds; Females 35 to 50 pounds
Proportion - Off Square; slightly longer than tall
Substance - Strong substantial bone; solidly built, Muscular build
Temperament - spirited disposition, self willed, brave, very resistant to fatigue. A dog of exceptional intelligence and loyalty. Obedient for whom it works.