Female horse owners avoided aggression and were easy going. Snake owners were unconventional, informal, novelty seeking, and somewhat unpredictable. Bird owners were contented, courteous, expressive, social, and altruistic. An idea should be gleaned about the potential owner's personality before being shown prospective pets. This is obviously unrealistic.
Shelters have limited budgets and staff.
The average adopter spends an hour or less at the shelter before leaving with a pet in hand. An evaluation of the animals to be adopted is also necessary. The animals are frequently screened by volunteers who are emotionally invested in seeing that each animal finds a home, any home. Obviously, volunteers need to be educated in how to realistically evaluate the practical adoptive consequences for each shelter animal and for the potential adopter. Ideally, all animals should be immunized and spayed or neutered before adoption.