Terms Relating to Lie Detectors Explained – Letter J and K
Jackknife Procedure
Statistical technique sometimes used to test a model. All data sets are
used to develop a model except one, and the excluded set is tested against the
model. This method is repeated until all sets have been excluded once and
tested against the model built with the remaining data. This method produces
a distribution of outcomes constructed from the individual outcomes of each
data set, and is a method sometimes used to validate a model. Jackknife
procedures have been used in PDD algorithm development.
Karpman’s classification of lying
Classification of lies and their underlying motives. They are benign lies
(for social conventions), hysterical lies (to attract attention), defensive lies (to
avoid an adverse situation), compensatory lies (to impress another), malicious
lies (for gain), gossip (exaggeration), implied lies (deceive with partial truths),
“love intoxication” lies (idealistic exaggeration), and pathological lies (selfdestructive
or maladaptive). See: Karpman (1949).
Keeler, Leonarde
Student of John Larson and influential PDD pioneer. Among Keeler’s
accomplishments are: the addition of the electrodermal channel to the
polygraph, establishing the first PDD school, devising the Keeler Technique,
and popularizing the polygraph field.
Keeler Polygraph
Originally manufactured by the Western Electro-Mechanical Company,
this instrument was not produced after 1938. It had three tambours: one for
the cardiosphygmograph, another for the pneumograph, and a third for either a
second pneumograph or a muscular movement device. The kymograph could
be geared to move the graph paper 3, 6, or 12 inches per minute. Associated
Research, Inc. later produced the Keeler polygraph, similar to the original
design except it permitted a galvanograph channel, and the chart speeds were
6 and 12 inches per minute. The Keeler polygraph is no longer in production.
Keeler Technique
A Relevant/Irrelevant testing method devised by Leonarde Keeler and
used in single- and multiple-issue testing. While its popularity has declined
since the introduction of the CQT formats, it is still used by many PDD
examiners and is considered one of the profession’s acceptable techniques.
Key
The critical item in a series of similar but neutral items used in Peak of
Tension (POT) tests. In a known solution POT, the key is the relevant question
that contains the incriminating information that only a guilty person should
know. A key in a searching POT is the test item that holds information that
only the guilty person knows and the PDD examiner is trying to uncover. In
stimulation tests, the key is the question to which the examiner directs the
examinee to lie. Also see false key.
Key Word Method
Procedure employed during PDD testing in which the examinee is
instructed to provide not only a yes or no reply, but repeat an important word
from the test question. Based on the stimulus–stimulus theory in which
cognitive activity is involved as an intermediary step between a stimulus and a
response. The key word in the test question is associated with the concept it is
supposed to represent. The key word method is used to neutralize dissociation
countermeasures.
Kircher Features
Ensemble of measurable physiological features found in traditional
polygraph recordings that correlate highest with deception. They are:
respiration line length, electrodermal response amplitude, relative blood
pressure amplitude, and finger pulse amplitude. See: Kircher & Raskin
(1988).
Known Numbers Acquaintance Test
Stimulation test with several variants, it has as a central feature that the
critical item is known to both the examinee and the polygraph examiner prior
to the test. See stimulation test.
Known Solution Peak of Tension test (KSPOT)
Peak of Tension test in which the critical item, or key, is known only to
the investigator, polygraph examiner, a guilty person, or a person with
incriminating knowledge. The key is placed in a question series among other
items equally plausible to an innocent examinee and presented to the subject
to determine if a consistent physiologic arousal occurs to the key. Like all Peak
of Tension procedures, trend responses are used in addition to specific
responses to interpret the recordings. Also known as a “Type A” test to
graduates of the Keeler polygraph school.
Known Truth Question
Question in the Arther Technique based on a fabricated crime, but one
that appears plausible to the examinee. It serves to ensure that the examinee
is not responsive to all crime questions irrespective of guilt. The known truth
question also provides a powerful interrogational wedge during the posttest
phase for those examinees who have produced charts indicative of deception to
the actual crime, but not to the fabricated crime.
Kymograph
Motorized mechanism that moves strip chart paper at a specified rate.
The current standard in PDD is 6 inches per minute, though historically there
have been other speeds.
