Abstract
Structuralism, functionalism as well as behaviorism have been the three major approaches to the artificial intelligence (AI) research in history up to the present time. These approaches have made great progress in AI so far. On the other hand, however, all the three are facing critical difficulties and lack of mutual understanding to each other. An attempt was thus made in the paper to propose a different approach to the AI research, the cognitive approach that tries to explore in depth the cognitive mechanism of intelligence formation of intelligent systems. It is discovered, as result, that the cognitive mechanism of intelligence formation is a series of transformations that can converse the information to knowledge and further to intelligent strategy and the latter is the embodiment of intelligence in narrower sense. An interesting by-product is also found that the aforementioned three approaches appear to be harmoniously unified within the framework of the cognitive approach. A brief report was in this paper on the cognitive approach as well as the unification of the existed three AI approaches