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VALIDITYINDICATOR

PROFILE(VIP)

The validity indicator profile (VIP) is a measure of

response validity that is intended to be administered

concurrently within a battery of cognitive tests in a

forensic assessment. The VIP has two subtests (verbal

and nonverbal), containing 178 items in all. Curve

analysis of test responses classifies performance as

valid or invalid. Invalid performances are subclassi-

fied as inconsistent, irrelevant, or suppression (obvi-

ous malingering). The VIP has been validated in

several adult samples.

Forensic psychological testing often involves

assessment of cognitive functioning. Given the inher-

ent advantages of appearing impaired in many forensic

forums (e.g., litigated claims of injury, competency to

stand trial), it is important to provide a formal assess-

ment of the validity of test performance. Forensic

assessments that conclude that cognitive impairment

exists are below the standard of practice if they do not

include overt assessment of the validity of presenta-

tions in interviews or on psychological tests. A large

variety of response validity instruments exist. Most

response validity instruments depend on assessment of

memory performance. The VIP directly assesses

problem-solving ability and vocabulary.

Performance on the VIP is categorized as valid or

invalid. Valid performances, referred to as compliant,

reflect an intention to perform well and reveal sustained

effort throughout the test. Invalid performances are

classified as inconsistent, irrelevant, or suppressed.

Inconsistent performances reveal evidence of intention

to respond correctly but reflect inconsistent effort.

Irrelevant performances result from random responding

throughout the test. Performances classified as sup-

pressed demonstrate that the individual intended to

respond incorrectly on the test and exerted sustained

effort to respond incorrectly.

These classifications reflect a model of test validity

in which validity is evaluated by a cross-classification

of “intent” (intends to respond correctly or does not

intend to respond correctly) and “effort” (low to high).

Although most “malingering tests” in use are referred

to as “effort” tests and employ a dichotomous classi-

fication process that generally is construed to mean

“malingering” or “not malingering,” the VIP employs

a fourfold classification scheme to capture elements

of these two constructs. Construct validation of this

scheme demonstrates that compliant and inconsistent

performances could be distinguished on the basis of

effort, that inconsistent and irrelevant performances

could be distinguished on the basis of intent, and that

compliant and suppressed performances could be dis-

tinguished on the basis of intent.

The categorizations are accomplished by perfor-

mance curve analysis. The performance curves are a

summary of response accuracy plotted against item

difficulty. The VIP has two subtests, nonverbal and

verbal. The nonverbal subtest includes 100 picture-

matrix problems, and the verbal subtest includes

78 word-definition problems. The items within each

subtest span a hierarchy of difficulty, from very easy

to very difficult. The items are presented in a random-

ized order of difficulty. The test is typically completed

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