...his nose was as sharp as a pen, and a' babbled of green fields.
William Shakespeare, Henry V, II, iii, 16-7
The tests below constitute a series designed to assess your ability to estimate to what degree a simple image is filled with color, as measured by the number of pixels in the image that are that color, as opposed to white.
Each test has 10 items. In each item, you will be given five images. Four of them have the same number of colored, i.e. nonwhite, pixels. The other image has a different number of colored pixels.
Your task is to select the image that differs from the others in the proportion of it that is filled with color.
These tests are an assessment of the ability to perceive differences in the appearance of simple images. In some of the easier items, this ability manifests as an ability to distinguish the apparent brightness of simple images. In the more difficult items, this ability manifests as an ability to synthesize slight differences between visually perceived media into a judgment or estimation of some property.
The item type found in these tests is not known to be found on any professional intelligence tests. However, this item type seems to measure a basic cognitive process, and such processes were frequently the subjects of investigation and measurement in the earliest days of intelligence testing.
Sir Francis Galton, for example, measured abilities similar to the one these tests seem to measure. These abilities concerned the ability to distinguish between different sensations. For example, one studied was the ability to determine which of two objects of slightly different weights was heavier.