Fig. 1
From: Trash Taxonomy Tool: harmonizing classification systems used to describe trash in environments
The object in the center is being classified using the material and item hierarchies on the TTT website. In this example of classifying an unlabeled plastic bottle, we can tell that it is made out of hard plastic and is a beverage bottle. However, we cannot tell what type of beverage bottle it is, so it should be classified generically as a beverage bottle. The classes hard plastic and beverage bottles are chosen to best represent the object in as much detail as possible, without assuming beyond the specificity we can observe