Skip to main content

Lund University Publications

LUND UNIVERSITY LIBRARIES

Fixation classification: how to merge and select fixation candidates

Hooge, Ignace T. C. ; Niehorster, Diederick C. LU orcid ; Nyström, Marcus LU orcid ; Andersson, Richard and Hessels, Roy S. (2022) In Behavior Research Methods 54(6). p.2765-2776
Abstract
Eye trackers are applied in many research fields (e.g., cognitive science, medicine, marketing research). To give meaning to the eye-tracking data, researchers have a broad choice of classification methods to extract various behaviors (e.g., saccade, blink, fixation) from the gaze signal. There is extensive literature about the different classification algorithms. Surprisingly, not much is known about the effect of fixation and saccade selection rules that are usually (implicitly) applied. We want to answer the following question: What is the impact of the selection-rule parameters (minimal saccade amplitude and minimal fixation duration) on the distribution of fixation durations? To answer this question, we used eye-tracking data with... (More)
Eye trackers are applied in many research fields (e.g., cognitive science, medicine, marketing research). To give meaning to the eye-tracking data, researchers have a broad choice of classification methods to extract various behaviors (e.g., saccade, blink, fixation) from the gaze signal. There is extensive literature about the different classification algorithms. Surprisingly, not much is known about the effect of fixation and saccade selection rules that are usually (implicitly) applied. We want to answer the following question: What is the impact of the selection-rule parameters (minimal saccade amplitude and minimal fixation duration) on the distribution of fixation durations? To answer this question, we used eye-tracking data with high and low quality and seven different classification algorithms. We conclude that selection rules play an important role in merging and selecting fixation candidates. For eye-tracking data with good-to-moderate precision (RMSD < 0.5∘), the classification algorithm of choice does not matter too much as long as it is sensitive enough and is followed by a rule that selects saccades with amplitudes larger than 1.0∘ and a rule that selects fixations with duration longer than 60 ms. Because of the importance of selection, researchers should always report whether they performed selection and the values of their parameters. (Less)
Please use this url to cite or link to this publication:
author
; ; ; and
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Eye tracking, Fixation classification, Selection rules, Minimal fixation duration, Minimal saccade amplitude
in
Behavior Research Methods
volume
54
issue
6
pages
12 pages
publisher
Springer
external identifiers
  • pmid:35023066
  • scopus:85122794571
ISSN
1554-3528
DOI
10.3758/s13428-021-01723-1
language
English
LU publication?
yes
id
0d986104-bbe0-41af-a0ed-943eefb33b17
date added to LUP
2022-01-18 09:29:17
date last changed
2023-05-11 07:59:23
@article{0d986104-bbe0-41af-a0ed-943eefb33b17,
  abstract     = {{Eye trackers are applied in many research fields (e.g., cognitive science, medicine, marketing research). To give meaning to the eye-tracking data, researchers have a broad choice of classification methods to extract various behaviors (e.g., saccade, blink, fixation) from the gaze signal. There is extensive literature about the different classification algorithms. Surprisingly, not much is known about the effect of fixation and saccade selection rules that are usually (implicitly) applied. We want to answer the following question: What is the impact of the selection-rule parameters (minimal saccade amplitude and minimal fixation duration) on the distribution of fixation durations? To answer this question, we used eye-tracking data with high and low quality and seven different classification algorithms. We conclude that selection rules play an important role in merging and selecting fixation candidates. For eye-tracking data with good-to-moderate precision (RMSD &lt; 0.5∘), the classification algorithm of choice does not matter too much as long as it is sensitive enough and is followed by a rule that selects saccades with amplitudes larger than 1.0∘ and a rule that selects fixations with duration longer than 60 ms. Because of the importance of selection, researchers should always report whether they performed selection and the values of their parameters.}},
  author       = {{Hooge, Ignace T. C. and Niehorster, Diederick C. and Nyström, Marcus and Andersson, Richard and Hessels, Roy S.}},
  issn         = {{1554-3528}},
  keywords     = {{Eye tracking; Fixation classification; Selection rules; Minimal fixation duration; Minimal saccade amplitude}},
  language     = {{eng}},
  number       = {{6}},
  pages        = {{2765--2776}},
  publisher    = {{Springer}},
  series       = {{Behavior Research Methods}},
  title        = {{Fixation classification: how to merge and select fixation candidates}},
  url          = {{http://dx.doi.org/10.3758/s13428-021-01723-1}},
  doi          = {{10.3758/s13428-021-01723-1}},
  volume       = {{54}},
  year         = {{2022}},
}