Since our goal is to minimize G, rating an item with high uncertainty is useful; it will
eliminate the uncertainty about the rating of the chosen item. However, labeling an
item whose rating is uncertain does not necessarily accomplish the goal of reducing
the uncertainty of ratings for other items (e.g. labeling an outlier may only reduce
rating uncertainty for a few other similar items, such as when selecting item (c) in
the Zombie genre, or even none as in (d), shown in Figure 23.1.