The study looked at dogs that already knew a large number of words for different objects and watched them learn new names. They found that these dogs can also acquire new labels of objects indirectly by "eavesdropping", that is, without directly manipulating the object or receiving specific training. The authors compared this way of learning to the way human infants learn new words at about 1.5 years of age. In experiments, dogs heard people use new words for objects in their surroundings and were then able to correctly match these words to the corresponding objects. The study shows that, at least in some dogs with rich vocabularies, word learning mechanisms similar to early word acquisition in children are at work. The results suggest that these dogs do not require repeated direct pointing and rewarding when learning new names, but use information from normal human communication. The authors also point out that this type of learning only appeared in dogs that had previously mastered a large number of object names.