  This work presents a study on the extraction and analysis of a set of 101
categories of eye movement features from three types of eye movement events:
fixations, saccades, and post-saccadic oscillations. The eye movements were
recorded during a reading task. For the categories of features with multiple
instances in a recording we extract corresponding feature subtypes by
calculating descriptive statistics on the distributions of these instances. A
unified framework of detailed descriptions and mathematical formulas are
provided for the extraction of the feature set. The analysis of feature values
is performed using a large database of eye movement recordings from a normative
population of 298 subjects. We demonstrate the central tendency and overall
variability of feature values over the experimental population, and more
importantly, we quantify the test-retest reliability (repeatability) of each
separate feature. The described methods and analysis can provide valuable tools
in fields exploring the eye movements, such as in behavioral studies, attention
and cognition research, medical research, biometric recognition, and
human-computer interaction.
