Betty appears to be able to focus on both the shape and the spread of the
sampling distribution, using both dimensions in making her choices. When asked
about a sample of size 50 (part 4), she again appeals to the idea that “If it’s
randomly selected it should hopefully be going more toward a normal distribution,”
and considers graph D as too normal for a sample size of 50 and so chooses graph E
(both incorrect choices; see Figure 3). She did not appear to consider variation in
selecting the graphs, despite her earlier comments on variability; and she was not
able to clearly differentiate between the sample and the sampling distribution, thus
exemplifying the student who does not have complete integration of different
components of the concept.