Polygraph Glossary Scoring

event marker

Definition

Event markers are annotations placed on the polygraph chart to alert reviewers of significant events: question onset and offset, the examinee's answer, movements, talking, deep breaths, and other occurrences. Many event markers have universally accepted meanings within the polygraph profession.

What Is an Event Marker?

Event markers are annotations placed on the polygraph chart to document significant occurrences during the examination — question onset/offset, examinee answers, movements, coughing, deep breaths, external noises, and other noteworthy events. Many follow universally accepted conventions allowing any trained examiner to interpret charts from another examiner.

Types

Standard markers include: question onset marks, answer marks (yes/no responses), movement marks (from activity sensors or observation), cough marks, deep breath marks, talking marks (spontaneous verbalisation), and external event marks (noises, interruptions). Specific symbols vary by instrument software but follow consistent conventions.

Importance for Scoring

Event markers are essential for accurate scoring and quality control. When evaluating an analysis spot, the examiner needs precise question timing to define the response onset window. Movement markers identify artefacts to exclude. During blind review, markers provide context for evaluating data quality.

Digital Implementation

In digital systems, event markers are entered via software buttons, time-stamped with millisecond precision, and stored in the chart data file — a significant improvement over manual pen annotations on analog chart paper. Part of the broader chart markings system.

Cross-references

More scoring terms in this glossary

correlation Correlation measures how one variable changes with another, ranging from -1.00 (perfect negative) to +1.00 (perfect p... Variance A statistical measure of the spread or dispersion of physiological response scores within a polygraph data set. Analy... chi-square test The chi-square test (χ²) is a non-parametric inferential statistical test used to evaluate relationships between cate... Bayesian Analysis A statistical approach used in polygraph scoring algorithms (including PolyScore) that calculates the posterior proba... ValidityTest Validity The degree to which a polygraph technique or scoring method accurately measures what it claims to measure — namely, t... Spearman Rank Correlation The Spearman Rank Correlation tests correlation between ordinal-level data. In PDD, it can assess inter-rater reliabi...

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