Frequently Asked Questions
- Q: WHAT IS A POLYGRAPH?
- A: A polygraph is the Psycho Physiological Detection of Deception or a test used to verify a person's truthfulness.
- Q: HOW DOES THE POLYGRAPH WORK?
- A: The polygraph as a computerised scientific diagnostic instrument composed of three or more recording components utilized to collect and record psycho physiological data when presented stimuli to a person by using a Generic PDD Exam.
- Q: POLYGRAPH AND THE SOUTH ADRICAN LAW?
- A: Polygraph testing is a fairly new concept in South Africa, especially in disputes relating to employment relationships. There is no legislation at this point to control the use of the test or to protect the employee's right against the abuse of a test.
- Q: WHEN IS THE EMPLOYER PERMITTED TO USE THE POLYGRAPH?
- A:Generally, employers are permitted to use the polygraph to investigate specific incidents where:
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• Employees had access to the property which is the subject of the investigation. • There is a reasonable suspicion that the employee was involved in the incident. • There has been economic loss or injury to the employer's business, like theft of company property. • The employer is combating dishonesty in positions of trust. • The employer is combating serious alcohol, illegal drugs or narcotics abuse and fraudulent behavior within the company. • The employer is combating deliberate falsification of documents and lies regarding true identity of the people involved. - Q: WHO GETS THE POLYGRAPH TEST RESULTS?
- A:
Forensic Psycho Physiologists have been accepted as expert witnesses whose evidence needs to be tested for reliability. The duty of the commissioner is to determine the admissibility and reliability of the evidence.
A polygraph test may not be interpreted as implying guilt but may be regarded as an aggravating factor especially where there is other evidence of misconduct.
- Q: WHAT IS THE STATUS OF A POLYGRAPH TEST AT CCMA?
- A:
Forensic Psycho Physiologists have been accepted as expert witnesses whose evidence needs to be tested for reliability. The duty of the commissioner is to determine the admissibility and reliability of the evidence.
A polygraph test may not be interpreted as implying guilt but may be regarded as an aggravating factor especially where there is other evidence of misconduct.
FACTS & Procedures
- SENSORS
- Polygraphs feature four to six sensors that are connected to the person submitting to the test. The four standard variables to be measured are pulse, blood pressure, rate of breath and volume of perspiration, but some machines also measure movement of the legs and arms.
- QUESTIONING
- At the beginning of a polygraph test, the examiner asks a few general questions, such as the person's name or what color shirt the person is wearing. This introductory set of questions is administered to establish a base line for the person being questioned, allowing the tester to distinguish between a person with a bad case of nerves and someone who is lying. After this control level is set, the hard questions begin. The tester analyzes the results as they are recorded on a piece of moving paper during the questioning.
- ACCURACY
- Polygraph testing is highly accurate. The American Polygraph Association has conducted over 250 studies on the accuracy of polygraph testing during the past 25 years. Recent research reveals that the accuracy of the new computerized polygraph system is close to 100%.