From his words it seems that he had understood very well the gist of the conversation and its message that letting babies sleep with their milk bottles can cause ear infection. Of course his prior knowledge in the matter is very scarce or none but by initially assimilating the idea and then verbalizing it to his mother, who takes the role of the authoritative, knowledgeable person in his life, Robbie activates this passive knowledge by constructing a logical connection based on his prior knowledge of how usually milk drips into one's ear from the perspective of a child and prior experience, perhaps, that is from the mouth through the cheek to the ear, turning it into a statement of explicit knowledge. The mother, who does know the issue quite well, that is she is an expert in the specific domain of knowledge, treats Robbie's statement as a nave concept and tries to reconstruct his knowledge by direct correction of the misconcepted idea. Robbie experiences a concept conflict, which, instead of leading to a process of new knowledge constructing, due to the mothers' attitude and approach, ends in a kind of defensive position demonstrated in his determination not to give up his beliefs, resembling the kind of assimilative peer interaction known as 'stonewalling' (Chan et al., 1997).
However, the strategy Robbie applies to comprehend the new information is not only assimilation, that is direct adding of new concepts, but also metacognition, because he managed to reflect on his own learning and put conscious efforts in accommodating the novel information within his personal system of knowledge..
The mother's behavior causes a concept crisis and tension arises between them. Not only her attitude, but also the use of "the Eustachian tube", a new piece of information for Robbie, which was just dropped without any further elaboration or clarification, leads to their argument. The expression must have gone beyond the ultimate level of comprehension of Robbie. Judging by his strong reaction he must have felt quite uncomfortable. Thus he does something quite typical of young learners - rejection. But later on when he spoke to his father, surprisingly enough, we see him with changed opinion and already assimilated new concept. What did actually happen How come this young boy fully comprehended such a complex issue I presume that by using the strategy of knowledge-building and self-reflection he replaced the contents of his schemas. But the final result of it led to surface structuring of his knowledge due to the application of imitation and copying practices by virtue of the little prior knowledge and caused by the more authoritative and expert individuals taking part into the learning event. We cannot say for sure that Robbie asked his father in order to validate his comprehension and reject his mother's, and only after he received a suggestive, friendly answer, he did accept the new concept; or that he had assimilated his mother's comprehension and just looked for validation from his father as the next authoritative figure in the family. For either suggestion I think Robbie failed to comprehend fully the new concept, because none of his parents did provide him with the needed details on the new issue and did facilitate his learning.
In "Knowledge building as a mediator" (Chan et al., 1997), the authors identify two approaches of concept comprehension in unfamiliar domain applied by learners: direct assimilation and knowledge