The morals of the preceding story are:

• Don't throw things at hungry bears

• To gather the most information about an object, use the smallest possible probe

A "hit" by any of the probes only told you that a bear existed somewhere within the diameter of the probe. Of the three probes, the marbles were the most effective means of gathering information because a marble "hit" told us that a bear existed somewhere within a very tiny area. We would call the basketball image "fuzzy" because there is a lot of uncertainty about the bear's real shape. As the probe size got smaller, the images became "sharper" because you were increasingly certain about the bear's shape. This quality of "sharpness" is called the resolution of an image.

The large basketballs don't give us a lot of information about the bear's outline, so we call this a "fuzzy" image.

The bear's outline is fairly clear, so this is a "sharp" image.