Coren defines three aspects of dog intelligence in the book: instinctive intelligence, adaptive intelligence, and working and obedience intelligence. Instinctive intelligence refers to a dog's ability to perform the tasks it was bred for, such as herding, pointing, fetching, guarding, or supplying companionship. Adaptive intelligence refers to a dog's ability to solve problems on its own. Working and obedience intelligence refers to a dog's ability to learn from humans.
The book's ranking focuses on working and obedience intelligence. Coren sent evaluation requests to American Kennel Club and Canadian Kennel Club obedience trial judges, asking them to rank breeds by performance, and received 199 responses, representing about 50 percent of obedience judges then working in North America. Assessments were limited to breeds receiving at least 100 judge responses. This methodology aimed to eliminate the excessive weight that might result from a simple tabulation of obedience degrees by breed. Its use of expert opinion followed precedent.
When Coren's list of breed intelligence first came out there was much media attention and commentary both pro and con. However over the years the ranking of breeds and the methodology used have come to be accepted as a valid description of the differences among dog breeds in terms of the trainability aspect of dog intelligence. In addition, measurements of canine intelligence using other methods have confirmed the general pattern of these rankings including a new study using owner ratings to rank dog trainability and intelligence. 79 ranks are given (plus 52 ties), a total of 131 breeds ranked:
Understanding of New Commands: Fewer than 5 repetitions.
Obey First Command: 95% of the time or better.