This result is perhaps not surprising, as a lot of the data is very sparse: for positions between 77 and 149, less than ten data points are Let us now turn to Table 1, which displays the results that were obtained by computing correlation coefficients on the raw data, i.e., without computing the mean entropy for all sentences with the same position.
genzel and Charniak (2002) show that this prediction holds for caching language models such as the ones proposed by Kuhn and de Mori (1990).