Construct Validity
of
the
UNIT
279
METHOD
Subjects
Participants were 104 1st- through 8th-grade and 10th-grade students enrolled in
public elementary, middle, and high schools in a rural county school district in East
Tennessee. Almost all participants were White (only two were minority). There were
61 females and 43 males, who ranged in age from 6 years, 7 months
to
17 years. Eligibility
for the free lunch program was used as a socioeconomic indicator: 28% of the par-
ticipants were eligible for the program. Participants were randomly selected from all
students who received parent permission to participate in the study. Students were selected
on a stratified basis by grade level: approximately 34 students were from grades 1-3;
37 from grades 4-6; 21 from grades 7-8; and 12
from
grade
10.
Characteristics
of
the
sample, including relatively small size, rural setting, and racial composition, limit gen-
eralizability
.
Instruments
The UNIT provides scores for
a
Full Scale
IQ,
as well as Memory, Reasoning, Symbolic, and Symbol-Reduced Quotients. The test
is in the process of standardization by Riverside Publishing Company and is being normed
on children and adolescents ranging in age from
5
years to 17 years,
11
months, with
stratification based on demographic variables
to
create a representative sample of the
United States population.
Field-testing data were available for approximately
60
subjects. The Rasch Model
procedure was used to determine item retention and ordering. Item analyses were con-
ducted to obtain standard error and infit and outfit indices as well as difficulty levels.
Items with unacceptable standard errors and poor fit characteristics were eliminated.
The standardization version
of
the UNIT was used in this study.
The UNIT is described by the authors as employing easily recognized international
symbols in an effort
to
reduce content bias for any race, culture, or ethnic group. Ad-
ministration procedures are conducted entirely through pantomime and demonstration.
The gestures used in the UNIT administration are drawn from gestures common in com-
munication within the United States and other cultures.
Universal Nonverbal Intelligence Test.
A
brief description
of
abilities assessed by each UNIT subtest follows:
1.
SymbolicMemory.
This is a test of short-term memory in which students can
use any internal language (symbols) to remember and code sequences.
2.
Cube Design.
This is a timed test requiring visual processing and nonverbal
reasoning; solution
of
this task is less amenable to verbal mediation via symbols.
3.
Spatial Memory.
This is a test of visual short-term memory with stimuli that
are not symbolically coded or recalled.
4.
Analogic Reasoning.
This is a test
of
reasoning ability
in
which symbolic
mediation will facilitate solution.
5.
Object Memory.
This is
a
test
of
visual short-term memory with stimuli that
can be readily coded and recalled through symbolic mediation.
6.
Mazes.
This is a timed visual motor test
of
reasoning and planning that is
less amenable
to
symbolic mediation.