Metacognition is knowing when you don’t know. For example, if someone asks you a question that you do not know the answer to, you will know that you do not know the answer. Another way to put it is knowing what you know.
Researchers at the DogStudies lab at the Max Planck Institute for the Science of Human History have determined that dogs have metacognition abilities. Their tests showed that dogs checked more often when they did not know where a reward was hidden. This illustrated to the researchers that dogs do tend to actively seek extra information when they have not seen where a reward is hidden which is an indication that the dogs knew that they did not know where the reward was.
A famous example of this is Chaser the Border Collie when she was asked to find a toy that she was not taught to find. Although it took her longer, she examined each toy in a group and finally, by process of elimination, picked the correct toy. She knew that she did not know the toy she was asked to find.
Scientists must research carefully, eliminating all possible flaws in their research. They must also design tests to prove or disprove their hypothesis which is not an easy task. But those of us who work with dogs and see what they can accomplish, do not need tests to prove their abilities. Dog and animals in general, have many more mental abilities then scientists can prove at the present. However, it is good that they do continue their research.