is skewed when the cucumbers are picked in a very early stage of ma-
turity. That is, the human eye cannot discriminate between the color of
the individuals: They all are equally dark green. Upon maturation the
distribution becomes less and less skewed, but still dark green, and ap-
proaches the normal Gaussian distribution. The amount of skewness, that
is, how many cucumbers seem to be outliers with respect to the Gauss-
ian distribution, depends, among other factors, on the growing condi-
tions.
Figure 7.9 gives an example for batches of cucumbers grown in two
different plant densities and with two levels of nutrients. It is evident
from this figure, that the skewness of the distribution has a marked ef-
fect on the development of the batch rated as acceptable. For batches
with equal mean color value, the batch with the largest skewness be-
comes unacceptable first.
How the distribution changes upon storage and further maturation can
be seen from Figure 7.10 where the background color of batches of ap-
ples was measured individually during the ripening at several constant
temperatures (unpublished, data M. Simi, University of Ljubljana,
Examples of Modeling Accetability 139FIGURE 7.9Distribution of green color over the individuals of the cucumber batches
for two levels of plant density (ld and hd) and two levels of nutrients (IEC and hEC)
during growing. (Courtesy ISHS.)