Polygraph Glossary Scoring

Three-Position Scoring

Definition

A simplified numerical scoring method using only three values: +1 (comparison response stronger), 0 (equal/no significant difference), and −1 (relevant response stronger). Used in the Empirical Scoring System (ESS). Research shows three-position scoring produces comparable accuracy to the more complex seven-position system while being easier to learn and more reliable across scorers.

What Is Three-Position Scoring?

Three-Position Scoring is a polygraph scoring concept. A simplified numerical scoring method using only three values: +1 (comparison response stronger), 0 (equal/no significant difference), and −1 (relevant response stronger). Used in the Empirical Scoring System (ESS). Research shows three-position scoring produces comparable accuracy to the more complex seven-position system while being easier to learn and more reliable across scorers.

Role of Three-Position Scoring in Polygraph Scoring

Scoring methodology is one of the most critical factors affecting polygraph accuracy. The evolution from subjective global evaluation to structured numerical scoring and automated algorithms has significantly improved the reliability and reproducibility of polygraph results, as measured by interrater reliability studies.

Modern scoring approaches analyse physiological responses across multiple channels — electrodermal activity (considered the most diagnostically powerful single channel), respiratory patterns, and cardiovascular changes — using validated Kircher features that have demonstrated replicable diagnostic value across decades of research.

Practical Application

APA Standards of Practice require the use of validated scoring methods for all diagnostic and screening polygraph examinations. The choice of scoring system directly affects the cut-scores applied for classification decisions (Deception Indicated, No Deception Indicated, or Inconclusive) and the overall balance between false positives and false negatives.

Related Terms

Understanding Three-Position Scoring in context requires familiarity with several related polygraph concepts:

Key Takeaways

Three-Position Scoring is an important concept within the field of Psychophysiological Detection of Deception. Whether you are a polygraph examiner, student at an APA-accredited training program, legal professional evaluating polygraph evidence, or a private individual preparing for a lie detector test, understanding this term and its relationship to other polygraph concepts will help you navigate the field with greater confidence and knowledge.

The science of polygraph testing has evolved significantly over more than 100 years, from the early work of William Moulton Marston and Leonarde Keeler to today's digital instruments and validated scoring algorithms. Every term in this glossary represents a piece of that scientific and professional heritage. For a comprehensive overview, visit the Polygraph Examiner Hub or use our examiner selection guide to find a professional examiner near you.

Cross-references

More scoring terms in this glossary

type II error A Type II error is the probability of not rejecting a false null hypothesis — failing to detect deception when it is ... Subtotal Score The numerical score for a single relevant question within a single chart. Individual subtotals are combined to produc... chi-square test The chi-square test (χ²) is a non-parametric inferential statistical test used to evaluate relationships between cate... true negative A true negative is a correct PDD decision that the examinee is not deceptive — an accurate outcome of truthfulness. S... type I error A Type I error is the probability of rejecting a true null hypothesis — incorrectly concluding deception when the exa... 7-position scale The 7-position scale is the most widely used system for assigning numerical values to physiological responses in PDD ...

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