The best way to find out is to learn about various breeds, visit with animals at the shelter, and speak with an adoption counselor for guidance. Most animal shelters have plenty of both. Of course, the size, appearance, and temperament of most mixed breed dogs can be predicted as well. After all, mixed breeds are simply combinations of different breeds. So if you can recognize the ancestry of a particular mixed breed puppy, you have a good chance of knowing how he'll turn out, too.
Mixed breeds offer several other advantages.
When you adopt a mixed breed, you have the benefit of getting the combined traits of two or more different breeds in one animal. You also get a dog who's likely to be free of genetic defects common to certain purebred dogs. When you adopt a mixed breed, you adopt a totally unique companion. While you're at the shelter, keep in mind that the shelter is a stressful place for any animal. Quite often, a dog's true colors won't show until he's away from other animals and the shelter environment.