The argument stated by Dr. Karp is wrong for numerous reasons. Primarily, the argument is based on interviews carried out by Dr. Karp and his team of graduate students. The argument fails to provide how many of the interviewed children belonged to Tertia, hence, rendering the conclusion that interview-centered approach is more significant than observation-based approach, invalid.
Dr. Karp states in his article that the interviews that his team took were carried out in islands that include Tertia, whereas, Dr. Field’s observation is based completely on Tertia. Hence, there may be a case that the children who Dr. Karp has interviewed might not have belonged to Tertia. The answers given by children belonging to other islands cannot be generalized for all islands and Tertia in particular.
Apart from giving the aforementioned evidence, Dr. Karp and his team have to also state the exact conversations that happen between children regarding their biological parents. What if, children talk about who their biological parents might be and try to predict them by matching their looks? Hence, amount of time that they take to talk about their biological parents is not enough to rule observation-based analysis out.
It may also be required from Dr. Karp and his team to interview large number of children in Tertia. An interview based on only small number of children may not be fully representative and valid. On contrary, it may also be possible that Dr. Field’s observation might have been based on his 10 years of experience in the island. Hence, to invalidate such an observation it is important to carry out a large scale of interviews.
Hence, aforementioned evidences are needed from the author and his team in order to completely rule out observation-based approach and carry out interview-based approach further to investigate the child rearing traditions.