http://sdtimes.com/sd-times-bl.... By measuring a developer's eye movements, physical and mental characteristics as they code, the researchers measured alertness and stress levels to predict when a programmer will make a coding error. In a paper entitled "Using Psycho-Physiological Measures to Assess Task Difficulty in Software Development" http://research.microsoft.com/..., the researchers summarized their study of 15 developers where they strapped an eye tracker, an electrodermal sensor and an EEG sensor to developers as they programmed various tasks. The study found that biometrics predicted task difficulty for a new developer 64.99% of the time. For a new development task, the researchers found biometrics to be 84.38% accurate. The researchers did not, however, comment on the invasiveness of biometric sensors to developers."