Normed for ages 2:6 to 4:11 (Usual age range is 2:6 to 3:5; Extended age range is 3:6 to 4:11).

On this subtest the child copies a two- or three-dimensional design using wooden blocks. Block Building is a measure of motor skill and visual perceptual encoding. It requires the child to have developed the notion of copying models. Although it is a non-verbal subtest, it may be influenced by verbal encoding strategies. It reflects aspects of problem solving ability; visual perceptual matching; hand-eye coordination; spatial orientation; visual motor skills; and ability with verbal and visual cues. "Block Building was created to measure the same abilities measured by the Copying subtest for young children not yet able to manipulate a pencil" (Elliott, 1990b, p. 43).

There are 12 items on this subtest. All children start with item 1. For the first item (building a tower with 8 blocks) the child’s response is scored as 2, 1, or 0 depending on the number of blocks used in the building. For the remaining items, the child is presented with either a two- or three-dimensional model from which to copy the design. The last 5 of the 12 items are presented as flat (two-dimensional) designs that are more challenging because they emphasize orientation and sequence.

The Block Building subtest is considered a fair measure of g across all ages (overall r = .51). Specificity is ample for the age groups.

Block Building is considered to possess low overall reliability (r = .77), with reliability coefficients ranging from .68 to .84 across all of the five age groups. It correlates best with Copying (r =.51) and least with Recall of Objects (r = .14). It has a moderate correlation with the GCA (r = .65).

Gf-Gc classification

In the Broad stratum definition of abilities, Block Building is considered to be a logical measure of Visual Processing (Gv). In the Narrow stratum of abilities, it is considered to be a probable measure of Visualization (VZ) (McGrew & Flanagan, 1998, p. 96).

The Block Building subtest is described on pages 67 to 71 in the DAS Administration and Scoring Manual and discussed on pages 43 and 44 in the DAS Introductory and Technical Handbook.

Examiners should study each design and practice building each before actually administering this subtest to a child. Fumbling will damage rapport, risk losing the child's attention, and penalize the child by giving an ambiguous demonstration to imitate. The Preschool record form shows each design and its correct orientation to the child.

According to the directions in the DAS Administration and Scoring Manual, rotations effect the scoring only on items 2 through 12. The examiner corrects all rotations.

Second attempts at building the designs are not allowed if the error is caused by a rotation. However, there are two situations in which the child should be given a second attempt. First, if on item number 1, the child builds the tower by placing the blocks on end (small side down) and fails to complete the tower, the examiner should demonstrate the correct way to build the tower and allow a second attempt. Score the better of the two attempts. Second, on items 1 through 7, the structure must remain free standing for at least 3 seconds (unless the child accidentally or playfully knocks down a stable structure). If the structure topples before 3 seconds, the examiner should allow the child a second attempt.