Which activity demonstrates placing objects in two or more groups based on differences in a single characteristic?

• A. Pulls out all the trucks from the vehicle bin.
• B. Puts all the red beads together and all the blue beads together.
• C. Puts pictures into piles of babies, older children, and grown up.
• D. Identifies fabric pieces as being scratchy or soft.

Answer: (B)

Sorting by a single observable trait to form distinct groups is the idea being tested. Piling red beads together and blue beads together uses one characteristic—color—to split the items into two non-overlapping groups. There’s no mixing of traits or multiple criteria involved, so it clearly demonstrates classifying objects based on differences in a single attribute.

The other activities either involve sorting by more than one criterion or present a less straightforward single-attribute division. For example, grouping by age creates several groups, which is still single-attribute, but it expands beyond a simple two-group split. Isolating trucks from a bin is a single-attribute sort as well, but it’s a specific category extraction rather than forming multiple clear groups by that attribute. The bead example is the most direct, unambiguous illustration of placing items into two distinct groups based on one characteristic.