Two articles on the use of the polygraph in counterintelligence, ["Spy Detection, Inc." and "A Test of the Test, Polygraph as Diagnostic Tool," Outlook, May 23], gave an incomplete and biased picture of the use of the polygraph by the national security community.

As one who has had some fairly close association with the use of the polygraph by the intelligence community for more than 40 years, I was surprised to learn that the polygraph "has achieved a new status in the world of counterintelligence in the past five years." What is it that happened in the past five years? Could it be that the reliability of the polygraph (generally considered about 85 percent) has improved to 95 percent, the reported view of the "top FBI polygraph official"?

The first article reported that the projected new polygraph screening by the Energy Department will mean that "investigations will begin, lives will be disrupted, careers may even be derailed." Indeed, what a terrible price to pay for the security of our nuclear secrets! Perhaps we could be told how many of the 40,000 tests given by the CIA and the FBI resulted in needless disruption of lives and derailed careers.

The article also left the impression that the polygraph test is a sole determinant on security issues, but it never is a sole determinant. It is used in conjunction with background investigations, interviews, national agency checks and other similar security tools. No personnel actions or separations are ever made on the basis of a questionable polygraph result, although further investigation is a normal outcome.

The second article seems to suggest that there has been no real research to support the validity of polygraph results. Nothing could be further from the truth. Extensive independent research by scientists in more than a dozen nations -- including Japan, Israel, Canada as well as the United States -- while differing on specifics, all indicates the value of the technique. Within the United States, research has been carried out at, among other places, the University of Chicago, the University of Texas, the University of Utah and Virginia Polytechnic Institute.

The polygraph has been an excellent security tool; it has speeded security investigations, identified foreign agents, pinpointed illegal drug use, identified potentially dangerous foreign contacts, cleared those unjustly accused, while at the same time saving taxpayer dollars.

M. J. LEVIN

Hillandale, Md.