Will they allow it to roam loose, which is illegal and dangerous, or chain a dog up which is a frustrating, desolate, cruel existence. Tell them you will want to see the yard. Make sure the address exists and the neighborhood is suitable. Be wary of people who talk about having the pet live in the garage, on the back porch, in the yard or basement. They are probably not interested in making the animal a household companion.
Dogs are pack animals and require a tremendous amount of human interaction.
Unless the family spends 10 hours a day in the backyard, an intention to keep the dog outside at all times is an indication that the dog will be isolated and alone most if its lifetime. People with young children are often unlikely to have time to spend with a dog. Many parents seek a pet thinking that the pet will teach a child responsibility. This is unfair to the pet. Parents also think that the pet and children will entertain each other.