An expression to connote the ensemble of tracing features used in chart interpretation that have replicated scientific evidence. There are four often-overlapping validated features for breathing (suppression, apnea, slowing, baseline rise), three for electrodermal (phasic response amplitude, duration, and complexity), three for cardiograph (baseline rise and duration, and pulse amplitude increase), and one for vasomotor (reduction in tracing width). The actual number of features can vary depending on how the tracings are characterized. For example, respiratory apnea is a form of respiratory suppression, but in some chart interpretation regimens, they are counted separately. Moreover, there are wide individual differences in that certain examinees may present idiosyncratic features that do not generalize to other examinees.¬†Nevertheless, the “Defensible Dozen” is used as a convenient mnemonic device that focuses on those features that tend to be the most universal. See: Kircher, Kristjansson, Gardner, & Webb (2005); Krapohl, Stern & Bronkema (2003).