What is chart making in polygraph?
Because the original analog instruments recorded the data with several pens writing lines on a moving sheet of paper, the record of physiological responses during the polygraph test is known as the polygraph chart.
How do you grade a polygraph?
Each channel of the polygraph is scored individually. For any channel, if the control response is larger than the relevant response, the score is from +1 to +3, depending on the magnitude of the difference. If the relevant response is larger the score is from −1 to −3.
What is the difference between chart paper and polygraph?
NORMAL RESPONSE – is a tracing on the chart wherein the subject answered in irrelevant questions. POLYGRAPH EXAMINER – is one who conducts or administers test. CHART or POLYGRAMS – refers to the composite records of the Pneumograph, Galvanograph and Cardiosphymograph tracings recorded from series questions.
What is Sky question in polygraph?
Suspect-Knowledge-You (SKY) questions are optional questions that may be asked on charts two and three of the ZCT; they may not be asked on the You Phase ZCT.
What is a control question on a polygraph test?
Control questions concern misdeeds that are similar to those being investigated, but refer to the subject’s past and are usually broad in scope; for example, “Have you ever betrayed anyone who trusted you?” A person who is telling the truth is assumed to fear control questions more than relevant questions.
How do you read lie detector results?
The negative values indicate higher reaction on the relevant questions and the positive values indicate higher response on the control questions. A grand total score of +6 and greater indicates nondeception, -6 and less deception, and anything in between is considered an inconclusive result.
What is numerical scoring of polygraph data?
In numerical scoring of polygraph charts, examiners typically combine upper and lower respiration scores into one score as well. Respiration line length is a more sophisticated measurement, however, which an examiner cannot easily calculate from the paper chart.
What are the 3 steps of polygraph tests what happens in each?
A Polygraph test will usually take between 2 / 3 hours, sometimes longer and consists of 3 phases; a pre-test interview, collection of charts, and analysis of charts.
Does high blood pressure affect a lie detector test?
Can this condition affect the result of the polygraph examination? While the polygraph does measure and record blood pressure, hypertension does not cause physiological reactions that are characteristic of those obtained when a person is lying.
What are the six 6 types of polygraph questions?
Terms in this set (13)
- Primary Relevant. Pertains directly to a single behavior alleged in the target issue.
- Secondary Relevant. Tests for indirect involvement of the examinee: present / seeing / hearing.
- Evidence Connecting. Tests for possession of evidence, contraband or fruits of the crime.
- Guilty Knowledge Question.
What does NSR mean on a polygraph?
NDI / NSR. No Deception Indicated: Often referred to as the examinee was found truthful. No Significant Response: Often referred to as the examinee was found truthful.
What are the two kinds of control questions?
Two major variations of polygraph “Control Question” testing, the Zone Comparison (ZoC) and the Modified General Question Test (MGQT) were evaluated.
How do you read polygraph data?
Reading a Polygraph Test In general, a significant change like a faster heart rate, higher blood pressure or increased perspiration indicates that the person is lying. During the test, this is shown as a large line drawn on the paper. A smaller line (or no line at all) signifies a truth.
What is the minimum number of test should the examiner administer in polygraph examination?
Once the examination is underway, the examiner will administer a minimum number of three separate tests each lasting approximately 5 minutes — and a maximum number of six tests — wherein the examinee’s physiological data will be continuously collected, measured and recorded, onto polygraph charts, as he or she answers …
How are physiological data evaluated by the polygraph examiner?
These physiological data are evaluated by the polygraph examiner using a specifled numerical scoring system and/or statistically automated scoring algorithms. The latter are the main focus of this report.
What does a polygraph test measure?
The polygraph as an instrument has been recording changes in people’s relative blood pressure, respiration and the electrodermal response (palmar sweating or galvanic skin response) in some form since 1926. These psychophysiological responses, believed to be controlled by the autonomic 1
How is the autonomic nervous system used in polygraph testing?
The autonomic nervous system will, in most cases, increase the person’s blood pressure and sweating, and afiect the breathing rate. These physiological data are evaluated by the polygraph examiner using a specifled numerical scoring system and/or statistically automated scoring algorithms.
What is the objective of automated scoring algorithms for polygraph data?
The objective of automated scoring algorithms for polygraph data is to create reliable and statis- tically valid classiflcation schemes minimizing both false positive and false negative rates.