Normed for ages 5:0 to 17:11 (Usual age range is 6:0 to 17:11; Out of level
age range is 5:0 to 5:11).
This subtest assesses acquired verbal knowledge and language comprehension
and fluency as well as verbal inductive reasoning; vocabulary and verbal
development; logical and abstract thinking; and ability to distinguish between
essential and superficial features.
The Similarities subtest contains a total of 34 three-word items. Children
are read three words and asked to tell how they go together, what they all are,
or how they are similar. Responses are typically scored 1, or 0, although 6
items do provide the option for a 2-point response as well. Three different
starting points are available (age 5:0 to 6:11 start at item 1; 7:0 to 8:11
start at item 8; 9:0 to 17:11 start at item 13).
Factor analytic findings
The Similarities subtest is considered a fair measure of g across all ages
(overall r = .69). For ages 6:0 to 12:11, the g loading is considered fair,
while at the remaining upper ages (13:0 to 17:11) the g loading is considered
good. This subtest contributes substantially to the Verbal factor (loading =
.81). Specificity is ample for all age groups 6:0 to 15:11 and adequate for 16:0
Reliability and correlational highlights
Similarities is considered to possess low overall reliability (r = .79), with
reliability coefficients ranging from .73 to .84 across all of the 13 whole-age
groups. There may be a certain amount of chance involved in trying to think of a
correct link among the words instead of a no-credit, trivial, but also true
connection. Similarities correlates best with Word
Definitions (r =.64) and least with Recall of Objects - Delayed (r =
.15). It has a moderate correlation with the GCA (r = .75).
In the Broad stratum definition of abilities, Similarities is considered to
be a strong measure of Crystallized Intelligence (Gc). In the Narrow stratum of
abilities, it is considered to be a probable measure of Language Development
(LD) and a possible measure of Lexical Knowledge (VL) (McGrew & Flanagan,
1998, p. 124).
Administrative and interpretive considerations
The Similarities subtest is described on pages 228 to 240 in the DAS
Administration and Scoring Manualand
discussed on pages 60 and 61 in the DAS Introductory and Technical Handbook.
To aid examiners in the scoring of the subtest, correct and incorrect responses
are included in the same section of the Manual as the directions. The examples
given have been listed in alphabetical order to further aid the examiner in
finding and scoring items. If a child has difficulty understanding the oral
presentation of the target words or requests that the words be repeated, the
examiner may repeat the words only once.
Similarities differs dramatically in a number of ways from the subtest with
the same name on the Wechsler scales. The DAS provides three target words. This
allows a child who may not know the meaning of one of the three to use the other
two to develop a response. (How often has a child who did not understand the
meaning for the word TRIBE received a 0 score on that WISC-III Similarities
item?) The SB: FE Verbal Relations subtest asks the student to explain how three
words are alike and different from a fourth. The DAS also differs from the
Wechsler scales in that a child must respond with a superordinate class for the
stimulus words in order to earn credit. On the Wechsler Scales, a subordinate
response is given 1 point while the superordinate response is given 2 points,
after the first five items. Hypothetically two children can obtain the exact raw
score of 13 (and thus the same scaled score), one giving 13 one-point
subordinate responses while the other simply gives 4 two-point superordinate
responses after the first five items.
Again, the DAS calls for liberal questioning of responses. "Question a
response that is incorrect but that indicates some understanding. . . . On
2-point items, also question all 1-point responses" (Elliott, 1990a, p.
The Sample and the first two actual items administered are teaching items if
the child gives an incorrect response. The examiner acknowledges correct
responses to those items. The examiner may use any of four means of presenting
items, including simply saying the three stimulus words once the child
understands the task.