Hornof Anthony J, Halverson Tim
Department of Computer and Information Science, University of Oregon, Eugene, Oregon 97403-1202, USA.
Behav Res Methods Instrum Comput. 2002 Nov;34(4):592-604. doi: 10.3758/bf03195487.
In the course of running an eye-tracking experiment, one computer system or subsystem typically presents the stimuli to the participant and records manual responses, and another collects the eye movement data, with little interaction between the two during the course of the experiment. This article demonstrates how the two systems can interact with each other to facilitate a richer set of experimental designs and applications and to produce more accurate eye tracking data. In an eye-tracking study, a participant is periodically instructed to look at specific screen locations, or explicit required fixation locations (RFLs), in order to calibrate the eye tracker to the participant. The design of an experimental procedure will also often produce a number of implicit RFIs--screen locations that the participant must look at within a certain window of time or at a certain moment in order to successfully and correctly accomplish a task, but without explicit instructions to fixate those locations. In these windows of time or at these moments, the disparity between the fixations recorded by the eye tracker and the screen locations corresponding to implicit RFLs can be examined, and the results of the comparison can be used for a variety of purposes. This article shows how the disparity can be used to monitor the deterioration in the accuracy of the eye tracker calibration and to automatically invoke a recalibration procedure when necessary. This article also demonstrates how the disparity will vary across screen regions and participants and how each participant's unique error signature can be used to reduce the systematic error in the eye movement data collected for that participant.
在进行眼动追踪实验的过程中，通常一个计算机系统或子系统向参与者呈现刺激并记录手动反应，另一个则收集眼动数据，在实验过程中两者之间几乎没有交互。本文展示了这两个系统如何相互作用，以促进更丰富的实验设计和应用，并产生更准确的眼动追踪数据。在眼动追踪研究中，会定期指示参与者看向特定的屏幕位置，即明确要求的注视位置（RFL），以便将眼动仪校准到参与者身上。实验程序的设计通常还会产生一些隐含的RFI——参与者必须在特定的时间窗口内或特定时刻看向的屏幕位置，以便成功且正确地完成一项任务，但没有明确指示要注视这些位置。在这些时间窗口或时刻，可以检查眼动仪记录的注视点与对应于隐含RFL的屏幕位置之间的差异，并且比较结果可用于多种目的。本文展示了如何利用这种差异来监测眼动仪校准精度的下降，并在必要时自动调用重新校准程序。本文还展示了这种差异在不同屏幕区域和参与者之间如何变化，以及如何利用每个参与者独特的误差特征来减少为该参与者收集的眼动数据中的系统误差。
